/* ===================================
   Variables & Design Tokens
   =================================== */
:root {
    --color-blue-dark: #0a1628;
    --color-blue-primary: #1a365d;
    --color-blue-medium: #2c5282;
    --color-blue-light: #4299e1;
    --color-blue-accent: #63b3ed;
    --color-red-dark: #9b2c2c;
    --color-red-primary: #c53030;
    --color-red-medium: #e53e3e;
    --color-red-light: #fc8181;
    --color-red-accent: #feb2b2;
    
    --font-display: 'Playfair Display', Georgia, serif;
    --font-body: 'Work Sans', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-mono: 'Source Code Pro', 'Fira Code', monospace;
    
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    --spacing-3xl: 4rem;
    --spacing-4xl: 6rem;
    
    --transition-fast: 150ms ease;
    --transition-base: 250ms ease;
    --transition-slow: 400ms ease;
    
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 20px;
    --radius-full: 9999px;
    
    /* Dark Mode (default) */
    --bg-primary: #0a1628;
    --bg-secondary: #0d1e36;
    --bg-tertiary: #1a365d;
    --bg-card: rgba(255, 255, 255, 0.02);
    --bg-card-hover: rgba(255, 255, 255, 0.05);
    --bg-header: rgba(10, 22, 40, 0.85);
    --bg-footer: rgba(10, 22, 40, 0.9);
    --text-primary: #ffffff;
    --text-secondary: #cbd5e0;
    --text-tertiary: #a0aec0;
    --text-muted: #718096;
    --border-color: rgba(66, 153, 225, 0.1);
    --border-color-hover: rgba(66, 153, 225, 0.3);
    --accent-primary: #e53e3e;
    --accent-secondary: #4299e1;
    --accent-light: #63b3ed;
    --grid-color: rgba(66, 153, 225, 0.03);
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.2);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.3);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.3);
}

[data-theme="light"] {
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    --bg-card: #ffffff;
    --bg-card-hover: #f8fafc;
    --bg-header: rgba(255, 255, 255, 0.95);
    --bg-footer: #f1f5f9;
    --text-primary: #1a202c;
    --text-secondary: #4a5568;
    --text-tertiary: #718096;
    --text-muted: #a0aec0;
    --border-color: rgba(26, 54, 93, 0.1);
    --border-color-hover: rgba(26, 54, 93, 0.2);
    --accent-primary: #e53e3e;
    --accent-secondary: #2c5282;
    --accent-light: #4299e1;
    --grid-color: rgba(26, 54, 93, 0.03);
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.08);
}

/* Reset */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
    font-family: var(--font-body);
    font-weight: 400;
    line-height: 1.6;
    color: var(--text-secondary);
    background-color: var(--bg-primary);
    min-height: 100vh;
    overflow-x: hidden;
    transition: background-color var(--transition-base), color var(--transition-base);
}
a { color: inherit; text-decoration: none; transition: color var(--transition-fast); }
ul { list-style: none; }
img { max-width: 100%; height: auto; display: block; }
button { font-family: inherit; cursor: pointer; border: none; background: none; }

.grid-background {
    position: fixed; top: 0; left: 0; width: 100%; height: 100%;
    background-image: linear-gradient(var(--grid-color) 1px, transparent 1px), linear-gradient(90deg, var(--grid-color) 1px, transparent 1px);
    background-size: 50px 50px; pointer-events: none; z-index: -1;
}

/* Typography */
h1, h2, h3, h4, h5, h6 { font-family: var(--font-display); font-weight: 600; line-height: 1.2; color: var(--text-primary); transition: color var(--transition-base); }
h1 { font-size: clamp(2.5rem, 5vw, 4rem); }
h2 { font-size: clamp(1.75rem, 3vw, 2.5rem); }
h3 { font-size: clamp(1.25rem, 2vw, 1.5rem); }
p { color: var(--text-tertiary); transition: color var(--transition-base); }

/* Layout */
main { background: linear-gradient(180deg, var(--bg-primary) 0%, var(--bg-secondary) 100%); min-height: 100vh; transition: background var(--transition-base); }
section { padding: var(--spacing-4xl) var(--spacing-xl); }

/* Header */
.main-header { position: fixed; top: 0; left: 0; right: 0; z-index: 1000; padding: var(--spacing-md) var(--spacing-xl); background: var(--bg-header); backdrop-filter: blur(12px); border-bottom: 1px solid var(--border-color); transition: background var(--transition-base), border-color var(--transition-base); }
.navbar { max-width: 1200px; margin: 0 auto; display: flex; justify-content: space-between; align-items: center; }
.logo { display: flex; align-items: center; gap: var(--spacing-sm); }
.logo-symbol { font-size: 1.75rem; font-family: var(--font-display); color: var(--accent-primary); font-weight: 700; }
.logo-text { font-family: var(--font-display); font-size: 1.25rem; font-weight: 600; color: var(--text-primary); transition: color var(--transition-base); }
.nav-links { display: flex; gap: var(--spacing-xl); }
.nav-links a { font-size: 0.95rem; font-weight: 500; color: var(--text-tertiary); position: relative; padding: var(--spacing-xs) 0; transition: color var(--transition-base); }
.nav-links a::after { content: ''; position: absolute; bottom: -2px; left: 0; width: 0; height: 2px; background: linear-gradient(90deg, var(--accent-primary), var(--accent-light)); transition: width var(--transition-base); }
.nav-links a:hover, .nav-links a.active { color: var(--text-primary); }
.nav-links a:hover::after, .nav-links a.active::after { width: 100%; }

/* Theme Toggle */
.theme-toggle { display: flex; align-items: center; justify-content: center; width: 40px; height: 40px; border-radius: var(--radius-md); background: var(--bg-card); border: 1px solid var(--border-color); cursor: pointer; transition: all var(--transition-base); margin-left: var(--spacing-md); }
.theme-toggle:hover { background: var(--bg-card-hover); border-color: var(--border-color-hover); transform: scale(1.05); }
.theme-toggle svg { width: 20px; height: 20px; color: var(--text-secondary); transition: color var(--transition-base); }
.theme-toggle .sun-icon { display: none; }
.theme-toggle .moon-icon { display: block; }
[data-theme="light"] .theme-toggle .sun-icon { display: block; }
[data-theme="light"] .theme-toggle .moon-icon { display: none; }

.mobile-menu-btn { display: none; flex-direction: column; gap: 5px; padding: var(--spacing-sm); }
.mobile-menu-btn span { display: block; width: 24px; height: 2px; background: var(--text-primary); transition: var(--transition-base); }

/* Hero */
.hero { min-height: 100vh; display: flex; align-items: center; padding-top: 100px; position: relative; overflow: hidden; }
.hero-content { flex: 1; max-width: 600px; z-index: 1; }
.hero-badge { display: inline-flex; align-items: center; gap: var(--spacing-sm); background: var(--bg-card); border: 1px solid var(--border-color); padding: var(--spacing-sm) var(--spacing-md); border-radius: var(--radius-full); font-size: 0.85rem; color: var(--accent-light); margin-bottom: var(--spacing-xl); animation: fadeInUp 0.6s ease forwards; transition: background var(--transition-base), border-color var(--transition-base); }
.badge-dot { width: 8px; height: 8px; background: var(--accent-primary); border-radius: 50%; animation: pulse 2s infinite; }
@keyframes pulse { 0%, 100% { opacity: 1; transform: scale(1); } 50% { opacity: 0.5; transform: scale(1.2); } }
.hero-title { margin-bottom: var(--spacing-lg); }
.title-line { display: block; animation: fadeInUp 0.6s ease forwards; animation-delay: 0.1s; opacity: 0; }
.title-line.highlight { background: linear-gradient(135deg, var(--accent-primary), var(--accent-light)); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; animation-delay: 0.2s; }
.hero-description { font-size: 1.125rem; color: var(--text-tertiary); margin-bottom: var(--spacing-2xl); animation: fadeInUp 0.6s ease forwards; animation-delay: 0.3s; opacity: 0; transition: color var(--transition-base); }
.hero-cta { display: flex; gap: var(--spacing-md); animation: fadeInUp 0.6s ease forwards; animation-delay: 0.4s; opacity: 0; }
@keyframes fadeInUp { from { opacity: 0; transform: translateY(20px); } to { opacity: 1; transform: translateY(0); } }
.hero-visual { flex: 1; position: relative; min-height: 400px; }
.math-decoration { position: absolute; right: 0; top: 50%; transform: translateY(-50%); }
.formula { font-family: var(--font-mono); color: var(--text-muted); font-size: 1.25rem; padding: var(--spacing-sm) var(--spacing-md); white-space: nowrap; animation: floatFormula 6s ease-in-out infinite; opacity: 0.4; }
.formula-1 { animation-delay: 0s; }
.formula-2 { animation-delay: 2s; transform: translateX(40px); }
.formula-3 { animation-delay: 4s; transform: translateX(20px); }
@keyframes floatFormula { 0%, 100% { transform: translateY(0) translateX(0); opacity: 0.3; } 50% { transform: translateY(-10px) translateX(10px); opacity: 0.5; } }
.geometric-shapes { position: absolute; width: 100%; height: 100%; pointer-events: none; }
.shape { position: absolute; border: 2px solid; opacity: 0.15; animation: rotateShape 20s linear infinite; }
.shape-1 { width: 300px; height: 300px; border-color: var(--accent-light); border-radius: 30% 70% 70% 30% / 30% 30% 70% 70%; right: 10%; top: 20%; }
.shape-2 { width: 200px; height: 200px; border-color: var(--accent-primary); right: 30%; top: 40%; animation-direction: reverse; animation-duration: 15s; }
.shape-3 { width: 150px; height: 150px; border-color: var(--text-muted); border-radius: 50%; right: 15%; top: 60%; animation-duration: 25s; }
@keyframes rotateShape { from { transform: rotate(0deg); } to { transform: rotate(360deg); } }

/* Buttons */
.btn { display: inline-flex; align-items: center; gap: var(--spacing-sm); padding: var(--spacing-md) var(--spacing-xl); font-size: 0.95rem; font-weight: 500; border-radius: var(--radius-md); transition: all var(--transition-base); }
.btn-primary { background: linear-gradient(135deg, var(--accent-primary), var(--color-red-dark)); color: #ffffff; box-shadow: 0 4px 15px rgba(229, 62, 62, 0.3); }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 6px 20px rgba(229, 62, 62, 0.4); }
.btn-secondary { background: transparent; color: var(--text-primary); border: 1px solid var(--border-color); transition: all var(--transition-base); }
.btn-secondary:hover { background: var(--bg-card-hover); border-color: var(--border-color-hover); }
.btn-full { width: 100%; justify-content: center; }

/* Section Headers */
.section-header { text-align: center; margin-bottom: var(--spacing-3xl); }
.section-tag { display: inline-block; font-family: var(--font-mono); font-size: 0.8rem; text-transform: uppercase; letter-spacing: 2px; color: var(--accent-primary); margin-bottom: var(--spacing-sm); }
.section-footer { text-align: center; margin-top: var(--spacing-2xl); }
.link-more { display: inline-flex; align-items: center; gap: var(--spacing-sm); color: var(--accent-light); font-weight: 500; transition: var(--transition-base); }
.link-more:hover { color: var(--text-primary); gap: var(--spacing-md); }

/* Page Header */
.page-header { padding-top: 140px; padding-bottom: var(--spacing-3xl); text-align: center; background: linear-gradient(180deg, var(--bg-tertiary) 0%, transparent 100%); transition: background var(--transition-base); }
.page-header-content { max-width: 600px; margin: 0 auto; }
.page-header h1 { margin-bottom: var(--spacing-md); }
.page-header p { font-size: 1.125rem; }

/* Featured Section */
.featured-section { background: var(--bg-secondary); transition: background var(--transition-base); }
.projects-preview { display: flex; flex-direction: column; gap: var(--spacing-md); }
.project-card { display: flex; align-items: center; gap: var(--spacing-xl); padding: var(--spacing-xl); background: var(--bg-card); border: 1px solid var(--border-color); border-radius: var(--radius-lg); transition: all var(--transition-base); cursor: pointer; box-shadow: var(--shadow-sm); }
.project-card:hover { background: var(--bg-card-hover); border-color: var(--border-color-hover); transform: translateX(10px); box-shadow: var(--shadow-md); }
.project-number { font-family: var(--font-display); font-size: 2.5rem; font-weight: 700; color: var(--text-muted); min-width: 80px; transition: color var(--transition-base); }
.project-card:hover .project-number { color: var(--accent-primary); }
.project-content { flex: 1; }
.project-content h3 { margin-bottom: var(--spacing-sm); transition: color var(--transition-base); }
.project-card:hover .project-content h3 { color: var(--accent-light); }
.project-content p { font-size: 0.95rem; margin-bottom: var(--spacing-sm); }
.project-tags { display: flex; flex-wrap: wrap; gap: var(--spacing-sm); }
.tag { font-family: var(--font-mono); font-size: 0.75rem; padding: var(--spacing-xs) var(--spacing-sm); background: var(--bg-tertiary); color: var(--accent-light); border-radius: var(--radius-sm); transition: background var(--transition-base); }
.project-arrow { font-size: 1.5rem; color: var(--text-muted); transition: var(--transition-base); }
.project-card:hover .project-arrow { color: var(--accent-primary); transform: translateX(5px); }

/* Skills Grid */
.skills-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); gap: var(--spacing-xl); }
.skill-card { padding: var(--spacing-xl); background: var(--bg-card); border: 1px solid var(--border-color); border-radius: var(--radius-lg); text-align: center; transition: all var(--transition-base); box-shadow: var(--shadow-sm); }
.skill-card:hover { background: var(--bg-card-hover); border-color: var(--accent-primary); transform: translateY(-5px); box-shadow: var(--shadow-md); }
.skill-icon { width: 64px; height: 64px; margin: 0 auto var(--spacing-md); display: flex; align-items: center; justify-content: center; background: var(--bg-tertiary); border-radius: var(--radius-md); color: var(--accent-light); transition: all var(--transition-base); }
.skill-card:hover .skill-icon { color: var(--accent-primary); }
.skill-card h3 { margin-bottom: var(--spacing-sm); font-size: 1.1rem; }
.skill-card p { font-size: 0.9rem; }

/* Projects Filter */
.projects-filter { padding: var(--spacing-xl); display: flex; justify-content: center; }
.filter-buttons { display: flex; flex-wrap: wrap; gap: var(--spacing-sm); justify-content: center; }
.filter-btn { padding: var(--spacing-sm) var(--spacing-lg); font-size: 0.9rem; font-weight: 500; color: var(--text-tertiary); background: transparent; border: 1px solid var(--border-color); border-radius: var(--radius-full); transition: all var(--transition-base); }
.filter-btn:hover { color: var(--text-primary); border-color: var(--border-color-hover); }
.filter-btn.active { color: #ffffff; background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary)); border-color: transparent; }

/* Projects Grid */
.projects-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(350px, 1fr)); gap: var(--spacing-xl); padding: 0 var(--spacing-xl) var(--spacing-4xl); }
.project-item { background: var(--bg-card); border: 1px solid var(--border-color); border-radius: var(--radius-lg); overflow: hidden; transition: all var(--transition-base); box-shadow: var(--shadow-sm); }
.project-item:hover { background: var(--bg-card-hover); border-color: var(--border-color-hover); transform: translateY(-5px); box-shadow: var(--shadow-xl); }
.project-item.hidden { display: none; }
.project-image { height: 200px; background: linear-gradient(135deg, var(--accent-secondary), var(--bg-tertiary)); position: relative; overflow: hidden; }
.project-placeholder { width: 100%; height: 100%; display: flex; align-items: center; justify-content: center; background: linear-gradient(135deg, rgba(66, 153, 225, 0.2) 0%, rgba(229, 62, 62, 0.1) 100%), repeating-linear-gradient(45deg, transparent, transparent 10px, rgba(255,255,255,0.02) 10px, rgba(255,255,255,0.02) 20px); }
.placeholder-icon { font-size: 3rem; opacity: 0.8; }
.project-info { padding: var(--spacing-xl); }
.project-meta { display: flex; justify-content: space-between; align-items: center; margin-bottom: var(--spacing-sm); }
.project-category { font-family: var(--font-mono); font-size: 0.75rem; text-transform: uppercase; letter-spacing: 1px; color: var(--accent-primary); }
.project-date { font-size: 0.8rem; color: var(--text-muted); }
.project-info h3 { margin-bottom: var(--spacing-sm); font-size: 1.25rem; }
.project-info p { font-size: 0.9rem; margin-bottom: var(--spacing-md); line-height: 1.5; }
.project-links { display: flex; gap: var(--spacing-md); margin-top: var(--spacing-md); padding-top: var(--spacing-md); border-top: 1px solid rgba(255, 255, 255, 0.05); }
.project-link { display: inline-flex; align-items: center; gap: var(--spacing-xs); font-size: 0.85rem; color: var(--text-tertiary); transition: color var(--transition-fast); }
.project-link:hover { color: var(--accent-light); }

/* About Page */
.about-content { padding-bottom: 0; }
.about-main { display: grid; grid-template-columns: 1fr 1fr; gap: var(--spacing-4xl); align-items: center; max-width: 1000px; margin: 0 auto; }
.about-text h2 { margin-bottom: var(--spacing-lg); }
.about-text p { margin-bottom: var(--spacing-md); font-size: 1.05rem; line-height: 1.8; }
.about-text strong { color: var(--text-primary); }
.about-image { position: relative; }
.profile-photo { width: 100%; aspect-ratio: 4/5; object-fit: cover; border-radius: var(--radius-lg); border: 3px solid rgba(66, 153, 225, 0.3); box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3); transition: transform var(--transition-base), box-shadow var(--transition-base); }
.profile-photo:hover { transform: scale(1.02); box-shadow: 0 25px 50px rgba(0, 0, 0, 0.4); border-color: var(--accent-primary); }

/* Timeline */
.timeline-section { max-width: 800px; margin: 0 auto; }
.timeline { position: relative; padding-left: var(--spacing-3xl); }
.timeline::before { content: ''; position: absolute; left: 7px; top: 0; bottom: 0; width: 2px; background: linear-gradient(180deg, var(--accent-primary), var(--accent-light)); }
.timeline-item { position: relative; padding-bottom: var(--spacing-2xl); }
.timeline-item:last-child { padding-bottom: 0; }
.timeline-marker { position: absolute; left: calc(-1 * var(--spacing-3xl) + 2px); top: 5px; width: 12px; height: 12px; background: var(--bg-primary); border: 2px solid var(--accent-primary); border-radius: 50%; }
.timeline-content { background: var(--bg-card); border: 1px solid var(--border-color); border-radius: var(--radius-md); padding: var(--spacing-xl); }
.timeline-date { font-family: var(--font-mono); font-size: 0.85rem; color: var(--accent-light); margin-bottom: var(--spacing-sm); }
.timeline-content h3 { font-size: 1.15rem; margin-bottom: var(--spacing-xs); }
.timeline-content p { font-size: 0.95rem; margin-bottom: var(--spacing-sm); }
.timeline-details { margin-top: var(--spacing-md); padding-left: var(--spacing-md); }
.timeline-details li { font-size: 0.9rem; color: var(--text-tertiary); margin-bottom: var(--spacing-xs); position: relative; padding-left: var(--spacing-md); }
.timeline-details li::before { content: '→'; position: absolute; left: 0; color: var(--accent-primary); }

/* Skills Detail */
.skills-detail-section { max-width: 900px; margin: 0 auto; }
.skills-categories { display: flex; flex-direction: column; gap: var(--spacing-2xl); }
.skill-category { background: var(--bg-card); border: 1px solid var(--border-color); border-radius: var(--radius-lg); padding: var(--spacing-xl); }
.skill-category h3 { font-size: 1.1rem; margin-bottom: var(--spacing-lg); padding-bottom: var(--spacing-sm); border-bottom: 1px solid rgba(255, 255, 255, 0.05); }
.skill-bars { display: flex; flex-direction: column; gap: var(--spacing-md); }
.skill-bar-item { display: flex; flex-direction: column; gap: var(--spacing-xs); }
.skill-bar-header { display: flex; justify-content: space-between; font-size: 0.9rem; }
.skill-bar-header span:first-child { color: var(--text-primary); font-weight: 500; }
.skill-bar-header span:last-child { color: var(--text-muted); font-size: 0.8rem; }
.skill-bar { height: 6px; background: rgba(255, 255, 255, 0.1); border-radius: var(--radius-full); overflow: hidden; }
.skill-bar-fill { height: 100%; background: linear-gradient(90deg, var(--accent-light), var(--accent-primary)); border-radius: var(--radius-full); transition: width 1s ease; }
.tools-grid { display: flex; flex-wrap: wrap; gap: var(--spacing-sm); }
.tool-item { padding: var(--spacing-sm) var(--spacing-md); background: var(--bg-tertiary); border: 1px solid var(--border-color); border-radius: var(--radius-md); transition: all var(--transition-base); }
.tool-item:hover { background: var(--bg-card-hover); border-color: var(--accent-light); }
.tool-name { font-family: var(--font-mono); font-size: 0.85rem; color: var(--accent-light); }
.math-skills { display: grid; grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); gap: var(--spacing-md); }
.math-skill-item { display: flex; align-items: center; gap: var(--spacing-sm); padding: var(--spacing-md); background: rgba(229, 62, 62, 0.05); border: 1px solid rgba(229, 62, 62, 0.1); border-radius: var(--radius-md); transition: all var(--transition-base); }
.math-skill-item:hover { background: rgba(229, 62, 62, 0.1); border-color: var(--accent-primary); }
.math-icon { font-family: var(--font-display); font-size: 1.25rem; font-weight: 700; color: var(--accent-primary); min-width: 30px; }
.math-skill-item span:last-child { font-size: 0.9rem; color: var(--text-tertiary); }

/* Interests */
.interests-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); gap: var(--spacing-lg); }
.interest-card { text-align: center; padding: var(--spacing-xl); background: var(--bg-card); border: 1px solid var(--border-color); border-radius: var(--radius-lg); transition: all var(--transition-base); }
.interest-card:hover { background: var(--bg-card-hover); border-color: var(--border-color-hover); transform: translateY(-5px); }
.interest-icon { font-size: 2.5rem; margin-bottom: var(--spacing-md); }
.interest-card h3 { font-size: 1rem; margin-bottom: var(--spacing-xs); }
.interest-card p { font-size: 0.85rem; }

/* Contact Page */
.contact-section { max-width: 1000px; margin: 0 auto; }
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: var(--spacing-3xl); }
.contact-info h2 { margin-bottom: var(--spacing-md); }
.contact-info > p { margin-bottom: var(--spacing-2xl); line-height: 1.7; }
.contact-methods { display: flex; flex-direction: column; gap: var(--spacing-lg); }
.contact-method { display: flex; gap: var(--spacing-md); align-items: flex-start; }
.contact-icon { width: 48px; height: 48px; display: flex; align-items: center; justify-content: center; background: var(--bg-tertiary); border-radius: var(--radius-md); color: var(--accent-light); flex-shrink: 0; }
.contact-details h3 { font-size: 0.9rem; font-family: var(--font-body); font-weight: 600; margin-bottom: var(--spacing-xs); }
.contact-details a, .contact-details span { font-size: 0.95rem; color: var(--text-tertiary); transition: color var(--transition-fast); }
.contact-details a:hover { color: var(--accent-light); }
.contact-form-wrapper { background: var(--bg-card); border: 1px solid var(--border-color); border-radius: var(--radius-lg); padding: var(--spacing-2xl); }
.contact-form h2 { margin-bottom: var(--spacing-xl); font-size: 1.25rem; }
.form-group { margin-bottom: var(--spacing-lg); }
.form-group label { display: block; font-size: 0.9rem; font-weight: 500; color: var(--text-tertiary); margin-bottom: var(--spacing-sm); }
.form-group input, .form-group textarea { width: 100%; padding: var(--spacing-md); font-family: var(--font-body); font-size: 0.95rem; color: var(--text-primary); background: rgba(255, 255, 255, 0.05); border: 1px solid var(--border-color); border-radius: var(--radius-md); transition: all var(--transition-base); }
.form-group input::placeholder, .form-group textarea::placeholder { color: var(--text-muted); }
.form-group input:focus, .form-group textarea:focus { outline: none; border-color: var(--accent-light); background: rgba(255, 255, 255, 0.08); }
.form-group textarea { resize: vertical; min-height: 120px; }
.form-note { margin-top: var(--spacing-md); text-align: center; }
.form-note small { font-size: 0.8rem; color: var(--text-muted); }

/* Availability Section */
.availability-section { max-width: 700px; margin: 0 auto; padding-top: 0; }
.availability-card { background: var(--bg-card); border: 1px solid var(--border-color); border-radius: var(--radius-lg); padding: var(--spacing-2xl); text-align: center; box-shadow: var(--shadow-md); transition: background var(--transition-base), border-color var(--transition-base); }
.availability-status { display: inline-flex; align-items: center; gap: var(--spacing-sm); font-size: 0.9rem; color: var(--accent-light); margin-bottom: var(--spacing-md); }
.status-dot { width: 10px; height: 10px; background: #48bb78; border-radius: 50%; animation: pulse 2s infinite; }
.availability-card h2 { font-size: 1.5rem; margin-bottom: var(--spacing-md); }
.availability-card > p { max-width: 500px; margin: 0 auto var(--spacing-xl); }
.availability-details { display: flex; justify-content: center; flex-wrap: wrap; gap: var(--spacing-xl); }
.detail-item { font-size: 0.9rem; color: var(--text-tertiary); }
.detail-item strong { color: var(--text-primary); }

/* CV Page */
.cv-download-header { margin-top: var(--spacing-xl); }
.cv-section { max-width: 900px; margin: 0 auto; padding: var(--spacing-xl) var(--spacing-xl) 0; }
.cv-contact-bar { display: flex; flex-wrap: wrap; justify-content: center; gap: var(--spacing-lg); padding: var(--spacing-lg); background: var(--bg-card); border: 1px solid var(--border-color); border-radius: var(--radius-lg); transition: background var(--transition-base), border-color var(--transition-base); }
.cv-contact-item { display: flex; align-items: center; gap: var(--spacing-sm); font-size: 0.9rem; color: var(--text-tertiary); }
.cv-contact-item a { color: var(--accent-light); transition: color var(--transition-fast); }
.cv-contact-item a:hover { color: var(--text-primary); }
.cv-contact-item svg { color: var(--accent-primary); flex-shrink: 0; }
.cv-section-header { margin-bottom: var(--spacing-lg); padding-bottom: var(--spacing-sm); border-bottom: 2px solid var(--accent-primary); }
.cv-section-header h2 { font-size: 1.5rem; text-transform: uppercase; letter-spacing: 2px; }
.cv-content { display: flex; flex-direction: column; gap: var(--spacing-xl); }
.cv-profile-text { font-size: 1.05rem; line-height: 1.8; color: var(--text-tertiary); }
.cv-profile-text strong { color: var(--text-primary); }
.cv-entry { background: var(--bg-card); border: 1px solid var(--border-color); border-radius: var(--radius-md); padding: var(--spacing-lg); transition: all var(--transition-base); box-shadow: var(--shadow-sm); }
.cv-entry:hover { background: var(--bg-card-hover); border-color: var(--border-color-hover); box-shadow: var(--shadow-md); }
.cv-entry-header { display: flex; justify-content: space-between; align-items: flex-start; gap: var(--spacing-md); margin-bottom: var(--spacing-sm); flex-wrap: wrap; }
.cv-entry-title h3 { font-size: 1.15rem; margin-bottom: var(--spacing-xs); }
.cv-location { font-size: 0.9rem; color: var(--text-tertiary); font-style: italic; }
.cv-date { font-family: var(--font-mono); font-size: 0.85rem; color: var(--accent-light); white-space: nowrap; background: var(--bg-tertiary); padding: var(--spacing-xs) var(--spacing-sm); border-radius: var(--radius-sm); transition: background var(--transition-base); }
.cv-subtitle { font-size: 0.95rem; color: var(--text-tertiary); margin-bottom: var(--spacing-sm); }
.cv-details { margin-top: var(--spacing-sm); padding-left: var(--spacing-lg); }
.cv-details li { font-size: 0.9rem; color: var(--text-tertiary); margin-bottom: var(--spacing-xs); position: relative; line-height: 1.6; }
.cv-details li::marker { color: var(--accent-primary); }
.cv-details li strong { color: var(--text-primary); }
.cv-skills-grid { display: grid; gap: var(--spacing-lg); }
.cv-skill-category h4 { font-family: var(--font-body); font-size: 1rem; font-weight: 600; color: var(--text-primary); margin-bottom: var(--spacing-md); transition: color var(--transition-base); }
.cv-skill-tags { display: flex; flex-wrap: wrap; gap: var(--spacing-sm); }
.cv-skill-tag { font-family: var(--font-mono); font-size: 0.8rem; padding: var(--spacing-xs) var(--spacing-md); background: var(--bg-tertiary); border: 1px solid var(--border-color); color: var(--accent-light); border-radius: var(--radius-full); transition: all var(--transition-base); }
.cv-skill-tag:hover { background: var(--bg-card-hover); border-color: var(--accent-light); }
.cv-skill-tag.soft { background: rgba(229, 62, 62, 0.1); border-color: rgba(229, 62, 62, 0.2); color: var(--accent-primary); }
.cv-skill-tag.soft:hover { background: rgba(229, 62, 62, 0.2); border-color: var(--accent-primary); }
.cv-skill-tag.lang { background: var(--bg-card); border-color: var(--border-color); color: var(--text-secondary); }
.cv-skill-tag.lang:hover { background: var(--bg-card-hover); border-color: var(--border-color-hover); }
.cv-download-section { max-width: 600px; margin: var(--spacing-3xl) auto; padding: 0 var(--spacing-xl); }
.cv-download-card { background: var(--bg-card); border: 1px solid var(--border-color); border-radius: var(--radius-lg); padding: var(--spacing-2xl); text-align: center; box-shadow: var(--shadow-md); transition: background var(--transition-base), border-color var(--transition-base); }
.cv-download-card h2 { font-size: 1.5rem; margin-bottom: var(--spacing-sm); }
.cv-download-card p { margin-bottom: var(--spacing-lg); }

/* Footer */
.main-footer { background: var(--bg-footer); border-top: 1px solid var(--border-color); padding: var(--spacing-3xl) var(--spacing-xl) var(--spacing-lg); transition: background var(--transition-base), border-color var(--transition-base); }
.footer-content { max-width: 1000px; margin: 0 auto; display: flex; justify-content: space-between; gap: var(--spacing-3xl); margin-bottom: var(--spacing-2xl); }
.footer-brand .logo-symbol { font-size: 2rem; display: block; margin-bottom: var(--spacing-md); }
.footer-brand p { font-size: 0.9rem; line-height: 1.6; }
.footer-links { display: flex; gap: var(--spacing-3xl); }
.footer-col h4 { font-family: var(--font-body); font-size: 0.9rem; font-weight: 600; color: var(--text-primary); margin-bottom: var(--spacing-md); transition: color var(--transition-base); }
.footer-col ul { display: flex; flex-direction: column; gap: var(--spacing-sm); }
.footer-col a { font-size: 0.9rem; color: var(--text-tertiary); transition: color var(--transition-fast); }
.footer-col a:hover { color: var(--accent-light); }
.footer-bottom { max-width: 1000px; margin: 0 auto; padding-top: var(--spacing-lg); border-top: 1px solid var(--border-color); text-align: center; }
.footer-bottom p { font-size: 0.85rem; color: var(--text-muted); }

/* Responsive */
@media (max-width: 1024px) {
    .main-header { padding: var(--spacing-md) var(--spacing-md); }
    .project-content { grid-template-columns: 1fr; }
    .project-sidebar { position: static; }
}

@media (max-width: 900px) {
    .hero { flex-direction: column; text-align: center; padding-top: 120px; }
    .hero-content { max-width: 100%; padding: 0 var(--spacing-md); }
    .hero-cta { justify-content: center; flex-wrap: wrap; }
    .hero-visual { display: none; }
    .about-main { grid-template-columns: 1fr; text-align: center; }
    .about-image { order: -1; max-width: 300px; margin: 0 auto; }
    .contact-grid { grid-template-columns: 1fr; }
    .projects-grid { grid-template-columns: 1fr; padding: 0 var(--spacing-md) var(--spacing-4xl); }
    .footer-content { flex-direction: column; text-align: center; }
    .footer-links { justify-content: center; }
    
    /* Page Header responsive */
    .page-header { padding: 120px var(--spacing-md) var(--spacing-2xl); }
    .page-header-content { padding: 0 var(--spacing-sm); }
    .page-header h1 { font-size: clamp(1.75rem, 6vw, 2.5rem); word-break: break-word; }
    .page-header p { font-size: 1rem; }
    
    /* Project Hero responsive */
    .project-hero { padding: 120px var(--spacing-md) var(--spacing-2xl); }
    .project-hero-content { padding: 0; }
    .project-hero-content h1 { font-size: clamp(1.5rem, 5vw, 2.5rem); word-break: break-word; }
    .project-tagline { font-size: 1rem; }
    
    /* Sidebar responsive */
    .project-sidebar { flex-direction: row; flex-wrap: wrap; gap: var(--spacing-md); }
    .sidebar-card { flex: 1 1 280px; min-width: 0; }
}

@media (max-width: 768px) {
    html { font-size: 15px; }
    
    .main-header { padding: var(--spacing-sm) var(--spacing-md); }
    .navbar { position: relative; }
    .logo-text { font-size: 1.1rem; }
    .logo-symbol { font-size: 1.5rem; }
    
    .nav-links { 
        display: none; 
        position: fixed; 
        top: 60px; 
        left: 0; 
        right: 0;
        width: 100%;
        background: var(--bg-header); 
        flex-direction: column; 
        padding: var(--spacing-lg); 
        gap: var(--spacing-md); 
        border-bottom: 1px solid var(--border-color);
        backdrop-filter: blur(12px);
        z-index: 100;
    }
    .nav-links.active { display: flex; }
    .mobile-menu-btn { display: flex; }
    .theme-toggle { position: absolute; right: 55px; top: 50%; transform: translateY(-50%); width: 36px; height: 36px; }
    .mobile-menu-btn.active span:nth-child(1) { transform: rotate(45deg) translate(5px, 5px); }
    .mobile-menu-btn.active span:nth-child(2) { opacity: 0; }
    .mobile-menu-btn.active span:nth-child(3) { transform: rotate(-45deg) translate(5px, -5px); }
    
    section { padding: var(--spacing-2xl) var(--spacing-md); }
    
    .project-card { flex-direction: column; text-align: center; padding: var(--spacing-lg); }
    .project-number { min-width: auto; font-size: 2rem; }
    .project-arrow { display: none; }
    .project-tags { justify-content: center; }
    
    .skills-grid { grid-template-columns: 1fr; }
    .timeline { padding-left: var(--spacing-xl); }
    .timeline-marker { left: calc(-1 * var(--spacing-xl) + 2px); }
    .timeline-content { padding: var(--spacing-md); }
    
    .cv-section { padding: var(--spacing-md) var(--spacing-md) 0; }
    .cv-contact-bar { flex-direction: column; align-items: flex-start; padding: var(--spacing-md); }
    .cv-entry-header { flex-direction: column; }
    .cv-date { align-self: flex-start; }
    .cv-entry { padding: var(--spacing-md); }
    
    .contact-section { padding: var(--spacing-xl) var(--spacing-md); }
    .contact-info h2 { font-size: 1.5rem; }
    .contact-form-wrapper { padding: var(--spacing-lg); }
    .contact-form h2 { font-size: 1.1rem; }
    
    .availability-section { padding: var(--spacing-xl) var(--spacing-md); }
    .availability-card { padding: var(--spacing-lg); }
    .availability-card h2 { font-size: 1.25rem; }
    
    .section-header h2 { font-size: clamp(1.5rem, 5vw, 2rem); }
    
    /* Results grid */
    .results-grid { grid-template-columns: 1fr; }
    .result-number { font-size: 2.5rem; }
    
    /* Tech stack */
    .tech-stack { justify-content: center; }
    .tech-badge { font-size: 0.8rem; padding: var(--spacing-xs) var(--spacing-sm); }
    
    /* Footer */
    .main-footer { padding: var(--spacing-2xl) var(--spacing-md) var(--spacing-md); }
    .footer-links { flex-direction: column; gap: var(--spacing-xl); }
}

@media (max-width: 480px) {
    html { font-size: 14px; }
    
    .hero { padding-top: 100px; min-height: auto; padding-bottom: var(--spacing-2xl); }
    .hero-title { font-size: 1.75rem; }
    .hero-description { font-size: 1rem; }
    .hero-cta { flex-direction: column; gap: var(--spacing-sm); }
    .hero-cta .btn { width: 100%; justify-content: center; }
    .hero-badge { font-size: 0.75rem; padding: var(--spacing-xs) var(--spacing-sm); }
    
    .page-header { padding: 100px var(--spacing-sm) var(--spacing-xl); }
    .page-header h1 { font-size: 1.5rem; }
    
    .project-hero { padding: 100px var(--spacing-sm) var(--spacing-xl); }
    .project-hero-content h1 { font-size: 1.4rem; }
    .project-meta-detail { flex-direction: column; align-items: flex-start; gap: var(--spacing-xs); }
    .project-category-tag, .project-date-tag { font-size: 0.7rem; }
    
    .back-link { font-size: 0.85rem; margin-bottom: var(--spacing-md); }
    
    section { padding: var(--spacing-xl) var(--spacing-sm); }
    
    .filter-buttons { flex-direction: column; width: 100%; }
    .filter-btn { width: 100%; text-align: center; }
    
    .project-item { border-radius: var(--radius-md); }
    .project-info { padding: var(--spacing-md); }
    .project-info h3 { font-size: 1.1rem; }
    
    .content-section h2 { font-size: 1.25rem; }
    .content-section p { font-size: 0.95rem; }
    
    .sidebar-card { padding: var(--spacing-md); }
    .sidebar-card h3 { font-size: 0.9rem; }
    .info-list li { flex-direction: column; gap: var(--spacing-xs); align-items: flex-start; }
    .sidebar-link { font-size: 0.85rem; padding: var(--spacing-sm); }
    
    .method-list li { padding: var(--spacing-sm); font-size: 0.9rem; }
    
    .math-item { padding: var(--spacing-md); }
    .math-item h4 { font-size: 0.95rem; }
    .math-item p { font-size: 0.85rem; }
    
    .availability-details { flex-direction: column; gap: var(--spacing-sm); }
    
    .contact-method { flex-direction: column; align-items: flex-start; gap: var(--spacing-sm); }
    .contact-icon { width: 40px; height: 40px; }
    .contact-details a, .contact-details span { font-size: 0.85rem; word-break: break-all; }
    
    .form-group input, .form-group textarea { padding: var(--spacing-sm); font-size: 0.9rem; }
    .btn { padding: var(--spacing-sm) var(--spacing-md); font-size: 0.9rem; }
    
    .cv-section-header h2 { font-size: 1.25rem; }
    .cv-entry-title h3 { font-size: 1rem; }
    .cv-details { padding-left: var(--spacing-sm); }
    .cv-details li { font-size: 0.85rem; }
    .cv-skill-tags { gap: var(--spacing-xs); }
    .cv-skill-tag { font-size: 0.75rem; padding: var(--spacing-xs) var(--spacing-sm); }
    
    .cv-download-section { padding: 0 var(--spacing-sm); }
    .cv-download-card { padding: var(--spacing-lg); }
    .cv-download-card h2 { font-size: 1.25rem; }
    
    .footer-brand p { font-size: 0.85rem; }
    .footer-col h4 { font-size: 0.85rem; }
    .footer-col a { font-size: 0.85rem; }
    .footer-bottom p { font-size: 0.8rem; }
    
    /* Indicators grid */
    .indicators-grid { grid-template-columns: repeat(2, 1fr); }
}

/* Animations */
.project-item, .skill-card, .interest-card, .timeline-item { opacity: 0; transform: translateY(20px); animation: fadeInUp 0.6s ease forwards; }
.project-item:nth-child(1) { animation-delay: 0.1s; }
.project-item:nth-child(2) { animation-delay: 0.2s; }
.project-item:nth-child(3) { animation-delay: 0.3s; }
.project-item:nth-child(4) { animation-delay: 0.4s; }
.project-item:nth-child(5) { animation-delay: 0.5s; }
.project-item:nth-child(6) { animation-delay: 0.6s; }
.skill-card:nth-child(1) { animation-delay: 0.1s; }
.skill-card:nth-child(2) { animation-delay: 0.2s; }
.skill-card:nth-child(3) { animation-delay: 0.3s; }
.skill-card:nth-child(4) { animation-delay: 0.4s; }
.timeline-item:nth-child(1) { animation-delay: 0.1s; }
.timeline-item:nth-child(2) { animation-delay: 0.3s; }
.timeline-item:nth-child(3) { animation-delay: 0.5s; }

/* ===================================
   Project Detail Page
   =================================== */
.project-detail { min-height: 100vh; }

.project-hero { 
    padding: 140px var(--spacing-xl) var(--spacing-3xl); 
    background: linear-gradient(180deg, var(--bg-tertiary) 0%, transparent 100%);
    transition: background var(--transition-base);
}

.back-link {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 0.9rem;
    color: var(--text-tertiary);
    margin-bottom: var(--spacing-xl);
    transition: color var(--transition-fast);
}

.back-link:hover {
    color: var(--accent-light);
}

.back-link svg {
    transition: transform var(--transition-fast);
}

.back-link:hover svg {
    transform: translateX(-4px);
}

.project-hero-content {
    max-width: 800px;
}

.project-meta-detail {
    display: flex;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

.project-category-tag {
    font-family: var(--font-mono);
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--accent-primary);
    padding: var(--spacing-xs) var(--spacing-md);
    background: rgba(229, 62, 62, 0.1);
    border: 1px solid rgba(229, 62, 62, 0.2);
    border-radius: var(--radius-full);
}

.project-date-tag {
    font-family: var(--font-mono);
    font-size: 0.8rem;
    color: var(--accent-light);
    padding: var(--spacing-xs) var(--spacing-md);
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-full);
}

.project-hero-content h1 {
    margin-bottom: var(--spacing-md);
    font-size: clamp(2rem, 4vw, 3rem);
}

.project-tagline {
    font-size: 1.25rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

.project-content {
    display: grid;
    grid-template-columns: 1fr 320px;
    gap: var(--spacing-3xl);
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-xl) var(--spacing-4xl);
}

.project-main {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-3xl);
}

.content-section h2 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-lg);
    padding-bottom: var(--spacing-sm);
    border-bottom: 2px solid var(--accent-primary);
}

.content-section p {
    font-size: 1.05rem;
    line-height: 1.8;
    margin-bottom: var(--spacing-md);
}

.project-figure {
    margin: 0;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.project-figure img {
    width: 100%;
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
    display: block;
}

.project-figure figcaption {
    font-size: 0.88rem;
    color: var(--text-muted);
    line-height: 1.6;
    padding: var(--spacing-sm) var(--spacing-md);
    border-left: 3px solid var(--accent-primary);
    background: var(--bg-card);
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

.method-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.method-list li {
    padding: var(--spacing-md);
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 0.95rem;
    line-height: 1.7;
    color: var(--text-tertiary);
    transition: all var(--transition-base);
}

.method-list li:hover {
    background: var(--bg-card-hover);
    border-color: var(--border-color-hover);
}

.method-list li strong {
    color: var(--accent-light);
}

.results-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-lg);
}

.result-card {
    padding: var(--spacing-xl);
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    text-align: center;
    transition: all var(--transition-base);
}

.result-card:hover {
    background: var(--bg-card-hover);
    border-color: var(--border-color-hover);
    transform: translateY(-3px);
}

.result-card.highlight {
    background: linear-gradient(135deg, rgba(229, 62, 62, 0.1), rgba(66, 153, 225, 0.1));
    border-color: var(--accent-primary);
}

.result-icon {
    font-size: 2.5rem;
    display: block;
    margin-bottom: var(--spacing-md);
}

.result-number {
    font-family: var(--font-display);
    font-size: 3rem;
    font-weight: 700;
    color: var(--accent-primary);
    display: block;
    margin-bottom: var(--spacing-sm);
}

.result-card h4 {
    font-size: 1rem;
    margin-bottom: var(--spacing-sm);
}

.result-card p {
    font-size: 0.85rem;
    margin-bottom: 0;
}

.tech-stack {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

.tech-badge {
    font-family: var(--font-mono);
    font-size: 0.85rem;
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    color: var(--accent-light);
    border-radius: var(--radius-md);
    transition: all var(--transition-base);
}

.tech-badge:hover {
    background: var(--bg-card-hover);
    border-color: var(--accent-light);
}

/* Project Sidebar */
.project-sidebar {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xl);
    position: sticky;
    top: 100px;
    height: fit-content;
}

.sidebar-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    transition: all var(--transition-base);
}

.sidebar-card h3 {
    font-size: 1rem;
    margin-bottom: var(--spacing-lg);
    padding-bottom: var(--spacing-sm);
    border-bottom: 1px solid var(--border-color);
}

.info-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.info-list li {
    display: flex;
    justify-content: space-between;
    font-size: 0.9rem;
}

.info-label {
    color: var(--text-muted);
}

.info-value {
    color: var(--text-primary);
    font-weight: 500;
}

.sidebar-links {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.sidebar-link {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md);
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 0.9rem;
    color: var(--text-secondary);
    transition: all var(--transition-base);
}

.sidebar-link:hover {
    background: var(--bg-card-hover);
    border-color: var(--accent-light);
    color: var(--accent-light);
}

.sidebar-link.download-link {
    background: linear-gradient(135deg, rgba(229, 62, 62, 0.1), rgba(229, 62, 62, 0.05));
    border-color: rgba(229, 62, 62, 0.2);
    color: var(--accent-primary);
}

.sidebar-link.download-link:hover {
    background: linear-gradient(135deg, rgba(229, 62, 62, 0.2), rgba(229, 62, 62, 0.1));
    border-color: var(--accent-primary);
}

/* Math Concepts */
.math-concepts {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.math-item {
    padding: var(--spacing-lg);
    background: var(--bg-card);
    border-left: 3px solid var(--accent-primary);
    border-radius: 0 var(--radius-md) var(--radius-md) 0;
}

.math-item h4 {
    font-size: 1rem;
    margin-bottom: var(--spacing-sm);
    color: var(--accent-light);
}

.math-item p {
    font-size: 0.9rem;
    margin-bottom: 0;
}

/* Indicators Grid */
.indicators-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    gap: var(--spacing-md);
}

.indicator-item {
    padding: var(--spacing-md);
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    text-align: center;
}

.indicator-item strong {
    display: block;
    font-family: var(--font-mono);
    color: var(--accent-light);
    margin-bottom: var(--spacing-xs);
}

.indicator-item span {
    font-size: 0.8rem;
    color: var(--text-muted);
}

/* Comparison Table */
.comparison-table {
    overflow-x: auto;
}

.comparison-table table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.9rem;
}

.comparison-table th,
.comparison-table td {
    padding: var(--spacing-md);
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.comparison-table th {
    font-weight: 600;
    color: var(--text-primary);
    background: var(--bg-tertiary);
}

.comparison-table td {
    color: var(--text-tertiary);
}

.comparison-table .highlight-row {
    background: rgba(229, 62, 62, 0.05);
}

.comparison-table .highlight-row td {
    color: var(--accent-primary);
    font-weight: 500;
}

/* Project Link Button in Cards */
.project-view-link {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    font-size: 0.85rem;
    color: var(--accent-light);
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    transition: all var(--transition-base);
}

.project-view-link:hover {
    background: var(--bg-card-hover);
    border-color: var(--accent-light);
    color: var(--text-primary);
}

/* Responsive for Project Detail - Now handled in main responsive section */