/* Color Variables */
/* ======================================================
   BASE (DEFAULT THEME VARIABLES)
   ====================================================== */
:root {
    --primary-color: #7da453;
    --primary-light: #a8c686;
    --primary-dark: #4f6f2f;
    --primary-gradient-start: #7da453;
    --primary-gradient-end: #9fcf6a;
    --accent-light: #f1f6ea;
    --accent-medium: #d6e5c3;
    --background: #fbfdf8;
    --surface: #ffffff;
    --text-primary: #2f3f1f;
    --text-secondary: #5f6f52;
    --text-muted: #8a9b7a;
    --border: #dde7cf;
    --shadow-sm: 0 4px 15px rgba(0,0,0,0.06);
    --shadow-md: 0 10px 30px rgba(0,0,0,0.12);
    --shadow-lg: 0 15px 40px rgba(0,0,0,0.18);
    --card-width: 350px;
}

/* ======================================================
   WINE
   ====================================================== */
[data-theme="wine"] {
    --primary-color: #722f37;          /* deep wine red */
    --primary-light: #9a4b55;          /* aged rosé */
    --primary-dark: #4a1c22;           /* cellar wine */
    --primary-gradient-start: #722f37;
    --primary-gradient-end: #952952;   /* berry finish */
    --accent-light: #f7e9ec;           /* wine foam */
    --accent-medium: #e6b8bf;
    --background: #fbf6f7;
    --surface: #ffffff;
    --text-primary: #5a011f;
    --text-secondary: #6b5555;
    --text-muted: #8f7a7a;
    --border: #e8d5d8;
    --shadow-sm: 0 4px 15px rgba(114, 47, 55, 0.08);
    --shadow-md: 0 10px 30px rgba(114, 47, 55, 0.14);
    --shadow-lg: 0 15px 40px rgba(114, 47, 55, 0.18);
}

/* ======================================================
   ORANGE
   ====================================================== */
[data-theme="orange"] {
    --primary-color: #e65100;
    --primary-light: #ff8f00;
    --primary-dark: #bf360c;
    --primary-gradient-start: #e65100;
    --primary-gradient-end: #ff9800;
    --accent-light: #fff3e0;
    --accent-medium: #ffcc80;
    --background: #fffaf5;
    --text-primary: #4e2600;
}

/* ======================================================
   GREEN
   ====================================================== */
[data-theme="green"] {
    --primary-color: #2e7d32;
    --primary-light: #4caf50;
    --primary-dark: #1b5e20;
    --primary-gradient-start: #2e7d32;
    --primary-gradient-end: #66bb6a;
    --accent-light: #e8f5e9;
    --accent-medium: #a5d6a7;
    --background: #f6fbf7;
    --text-primary: #1b3d1f;
}

/* ======================================================
   MAROON
   ====================================================== */
[data-theme="maroon"] {
    --primary-color: #7b1f2a;
    --primary-light: #a23b47;
    --primary-dark: #4f0f18;
    --primary-gradient-start: #7b1f2a;
    --primary-gradient-end: #b71c1c;
    --accent-light: #fbeaec;
    --accent-medium: #e6a1a8;
    --background: #faf6f7;
    --text-primary: #4a0d14;
}

/* ======================================================
   LAVENDER
   ====================================================== */
[data-theme="lavender"] {
    --primary-color: #7e57c2;
    --primary-light: #b39ddb;
    --primary-dark: #512da8;
    --primary-gradient-start: #7e57c2;
    --primary-gradient-end: #9575cd;
    --accent-light: #f3e5f5;
    --accent-medium: #d1c4e9;
    --background: #faf9fd;
    --text-primary: #3f2a5e;
}

/* ======================================================
   BLUE
   ====================================================== */
[data-theme="blue"] {
    --primary-color: #1976d2;
    --primary-light: #64b5f6;
    --primary-dark: #0d47a1;
    --primary-gradient-start: #1976d2;
    --primary-gradient-end: #42a5f5;
    --accent-light: #e3f2fd;
    --accent-medium: #bbdefb;
    --background: #f7fbff;
    --text-primary: #0d2b52;
}

/* ======================================================
   ROYAL BLUE
   ====================================================== */
[data-theme="royal-blue"] {
    --primary-color: #0b3c8c;
    --primary-light: #3f6fd1;
    --primary-dark: #07265a;
    --primary-gradient-start: #0b3c8c;
    --primary-gradient-end: #1e5ed6;
    --accent-light: #e8eefc;
    --accent-medium: #b3c7f5;
    --background: #f6f9ff;
    --text-primary: #061c3f;
}

/* ======================================================
   EMERALD
   ====================================================== */
[data-theme="emerald"] {
    --primary-color: #007f5f;
    --primary-light: #2bbf9b;
    --primary-dark: #004f3a;
    --primary-gradient-start: #007f5f;
    --primary-gradient-end: #00b386;
    --accent-light: #e6f7f2;
    --accent-medium: #9fe0cf;
    --background: #f5fcfa;
    --text-primary: #003d2d;
}

/* ======================================================
   BEIGE / CREAM
   ====================================================== */
[data-theme="beige"] {
    --primary-color: #b08968;
    --primary-light: #d6b89c;
    --primary-dark: #7f5f45;
    --primary-gradient-start: #b08968;
    --primary-gradient-end: #e6ccb2;
    --accent-light: #fdf6ee;
    --accent-medium: #f1dfcd;
    --background: #fefbf7;
    --text-primary: #4e3b2a;
}

/* ======================================================
   ROSE
   ====================================================== */
[data-theme="rose"] {
    --primary-color: #c0486f;
    --primary-light: #e07a9a;
    --primary-dark: #8b2f4c;
    --primary-gradient-start: #c0486f;
    --primary-gradient-end: #e36b8e;
    --accent-light: #fde7ee;
    --accent-medium: #f6b5c9;
    --background: #fff7fa;
    --text-primary: #5a0f2c;
}

/* ======================================================
   LEMON
   ====================================================== */
[data-theme="lemon"] {
    --primary-color: #f1c40f;
    --primary-light: #f9e27d;
    --primary-dark: #c9a20a;
    --primary-gradient-start: #f1c40f;
    --primary-gradient-end: #f7dc6f;
    --accent-light: #fffbe6;
    --accent-medium: #fff1a8;
    --background: #fffdf5;
    --text-primary: #5c4a00;
}

/* ======================================================
   YELLOW
   ====================================================== */
[data-theme="yellow"] {
    --primary-color: #f4b400;
    --primary-light: #ffd54f;
    --primary-dark: #c49000;
    --primary-gradient-start: #f4b400;
    --primary-gradient-end: #ffca28;
    --accent-light: #fff8e1;
    --accent-medium: #ffe082;
    --background: #fffdf7;
    --text-primary: #5a4200;
}

/* ======================================================
   IVORY
   ====================================================== */
[data-theme="ivory"] {
    --primary-color: #c9b79c;
    --primary-light: #e3d7c3;
    --primary-dark: #9f8f78;
    --primary-gradient-start: #c9b79c;
    --primary-gradient-end: #f1eadf;
    --accent-light: #fbf9f5;
    --accent-medium: #eee6d8;
    --background: #fefdfb;
    --text-primary: #4a4236;
}

/* ======================================================
   GOLD
   ====================================================== */
[data-theme="gold"] {
    --primary-color: #b8962e;
    --primary-light: #e0c76a;
    --primary-dark: #7a631a;
    --primary-gradient-start: #b8962e;
    --primary-gradient-end: #f5d76e;
    --accent-light: #fdf8e3;
    --accent-medium: #f0e0a6;
    --background: #fffdf6;
    --text-primary: #4a3b00;
}

/* ======================================================
   MATCHA
   ====================================================== */
[data-theme="matcha"] {
    --primary-color: #7da453;
    --primary-light: #a8c686;
    --primary-dark: #4f6f2f;
    --primary-gradient-start: #7da453;
    --primary-gradient-end: #9fcf6a;
    --accent-light: #f1f6ea;
    --accent-medium: #d6e5c3;
    --background: #fbfdf8;
    --text-primary: #2f3f1f;
}

/* ======================================================
   PEACOCK
   ====================================================== */
[data-theme="peacock"] {
    --primary-color: #0f4c5c;
    --primary-light: #2fa4a9;
    --primary-dark: #082f36;
    --primary-gradient-start: #0f4c5c;
    --primary-gradient-end: #1fa6a1;
    --accent-light: #e6f4f3;
    --accent-medium: #9edbd6;
    --background: #f7fbfb;
    --text-primary: #072a30;
}

/* General Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'EB Garamond', serif;
    line-height: 1.6;
    background: var(--background);
    color: var(--text-primary);
    overflow-x: hidden;
}

/* Hero Section */
.hero {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 200px;
    background: linear-gradient(135deg, var(--primary-gradient-start) 0%, var(--primary-gradient-end) 100%);
    color: white;
    text-align: center;
    z-index: 900;
    display: flex;
    flex-direction: column;
    justify-content: center;
    padding: 0 20px;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg width="100" height="100" xmlns="http://www.w3.org/2000/svg"><defs><pattern id="grid" width="100" height="100" patternUnits="userSpaceOnUse"><circle cx="50" cy="50" r="2" fill="white" opacity="0.1"/></pattern></defs><rect width="100%" height="100%" fill="url(%23grid)"/></svg>');
    opacity: 0.3;
    animation: heroPattern 20s linear infinite;
}

@keyframes heroPattern {
    from { transform: translate(0, 0); }
    to { transform: translate(100px, 100px); }
}

.hero-content {
    position: relative;
    z-index: 1;
    max-width: 800px;
    margin: 0 auto;
}

.hero h1 {
    font-size: 3.5rem;
    font-weight: 800;
    margin-bottom: 15px;
    letter-spacing: -1px;
    animation: fadeInDown 0.8s ease;
    text-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
}

.hero .tagline {
    font-size: 1.3rem;
    opacity: 0.95;
    margin-bottom: 30px;
    animation: fadeInUp 0.8s ease 0.2s both;
}

/* Navigation */
nav {
    position: fixed;
    top: 200px;
    left: 0;
    right: 0;
    height: 60px;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0 20px;
}

nav ul {
    list-style: none;
    display: flex;
    justify-content: center;
    gap: 35px;
    flex-wrap: wrap;
    padding: 0 20px;
}

nav a {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 600;
    font-size: 0.95rem;
    padding: 8px 16px;
    border-radius: 8px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
}

nav a::before {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transition: all 0.3s ease;
    transform: translateX(-50%);
}

nav a:hover::before {
    width: 80%;
}

nav a:hover {
    color: var(--primary-color);
    background: var(--accent-light);
    transform: translateY(-2px);
}

nav a.active {
    color: var(--primary-color);
    background: var(--accent-medium);
}

nav a.active::before {
    width: 80%;
}

/* Main Content Container */
.main-content {
    position: fixed;
    top: 260px;
    left: 0;
    right: 0;
    bottom: 60px;
    overflow: hidden;
    background: var(--background);
}

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    height: 100%;
}

/* Section Styles */
.section {
    display: none;
    height: 100%;
    overflow: hidden;
    animation: fadeInUp 0.4s ease;
}

.section.active {
    display: flex;
    flex-direction: column;
    overflow: visible;
}

.section-header {
    position: sticky;
    top: 0;
    text-align: center;
    background: var(--background);
    z-index: 100;
    padding: 20px 0;
    flex-shrink: 0;
}

.section-header h2 {
    font-size: 2.5rem;
    color: var(--text-primary);
    margin-bottom: 10px;
    position: relative;
    display: inline-block;
}

.section-header h2::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 4px;
    background: linear-gradient(to right, var(--primary-gradient-start), var(--primary-gradient-end));
    border-radius: 2px;
}

.section-header p {
    color: var(--text-muted);
    font-size: 1.1rem;
    max-width: 600px;
    margin: 20px auto 0;
}

/* Scrollable Content Area */
.scrollable-content {
    flex: 1;
    overflow-y: auto;
    overflow-x: hidden;
    padding: 20px 0;
    margin-right: -10px;
    padding-right: 10px;
}

.scrollable-content::-webkit-scrollbar {
    width: 10px;
}

.scrollable-content::-webkit-scrollbar-track {
    background: var(--accent-light);
    border-radius: 5px;
}

.scrollable-content::-webkit-scrollbar-thumb {
    background: var(--primary-color);
    border-radius: 5px;
}

.scrollable-content::-webkit-scrollbar-thumb:hover {
    background: var(--primary-dark);
}

/* About Section */
.about-content {
    background: var(--surface);
    padding: 40px;
    border-radius: 20px;
    box-shadow: var(--shadow-md);
    max-width: 900px;
    margin: 0 auto;
    line-height: 1.9;
    font-size: 1.05rem;
    color: var(--text-secondary);
    border: 1px solid var(--border);
    transition: all 0.3s ease;
}

.about-content:hover {
    box-shadow: var(--shadow-lg);
    border-color: var(--accent-medium);
}

/* Masonry Grid for Skills */
.masonry-grid {
    column-count: 3;
    column-gap: 30px;
}

.masonry-grid .skill-card {
    break-inside: avoid;
    margin-bottom: 30px;
    width: 100%;
}

/* Regular Grid for Projects, Research, Profiles */
.regular-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(var(--card-width), 1fr));
    gap: 30px;
    align-items: stretch;
}

/* Skill Cards */
.skill-card {
    background: var(--surface);
    padding: 30px;
    border-radius: 16px;
    box-shadow: var(--shadow-sm);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    border-left: 4px solid transparent;
    border: 1px solid var(--border);
    position: relative;
    overflow: hidden;
}

.skill-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(114, 47, 55, 0.05), transparent);
    transition: left 0.5s ease;
}

.skill-card:hover::before {
    left: 100%;
}

.skill-card:hover {
    transform: translateY(-5px) scale(1.02);
    box-shadow: var(--shadow-md);
    border-left-color: var(--primary-color);
    border-color: var(--accent-medium);
}

.skill-card h3 {
    color: var(--text-primary);
    font-size: 1.3rem;
    margin-bottom: 15px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.skill-card h3::before {
    content: '▸';
    color: var(--primary-color);
    font-size: 1.5rem;
    transition: transform 0.3s ease;
}

.skill-card:hover h3::before {
    transform: translateX(5px);
}

.skill-card ul {
    list-style: none;
    padding-left: 0;
}

.skill-card li {
    padding: 8px 0;
    color: var(--text-secondary);
    position: relative;
    padding-left: 20px;
    transition: all 0.2s ease;
}

.skill-card li:hover {
    color: var(--primary-color);
    transform: translateX(5px);
}

.skill-card li::before {
    content: '•';
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: bold;
}

/* Project/Research/Profile Cards */
.project-card,
.research-card,
.profile-card {
    background: var(--surface);
    padding: 35px;
    border-radius: 16px;
    box-shadow: var(--shadow-sm);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    border: 1px solid var(--border);
    position: relative;
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

.project-card::before,
.research-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 5px;
    background: linear-gradient(to right, var(--primary-gradient-start), var(--primary-gradient-end));
}

.project-card:hover,
.research-card:hover,
.profile-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
    border-color: var(--accent-medium);
}

.project-card h3,
.research-card h3,
.profile-card h3 {
    color: var(--text-primary);
    font-size: 1.4rem;
    margin-bottom: 15px;
    transition: color 0.3s ease;
}

.project-card:hover h3,
.research-card:hover h3,
.profile-card:hover h3 {
    color: var(--primary-color);
}

.project-card p,
.research-card p,
.profile-card p {
    color: var(--text-muted);
    line-height: 1.8;
    margin-bottom: 12px;
}

.project-card a,
.research-card a,
.profile-card a {
    display: inline-block;
    margin-top: auto;
    padding-top: 15px;
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    position: relative;
    padding-right: 20px;
}

.project-card a::after,
.research-card a::after,
.profile-card a::after {
    content: '→';
    position: absolute;
    right: 0;
    transition: transform 0.3s ease;
}

.project-card a:hover,
.research-card a :hover,
.profile-card a:hover {
    color: var(--primary-light);
}

.project-card a:hover::after,
.research-card a:hover::after,
.profile-card a:hover::after {
    transform: translateX(5px);
}

/* Contact Section */
.contact-content {
    display: flex;
    justify-content: center;
    align-items: flex-start;
    padding: 20px 0;
}

.contact-form {
    max-width: 600px;
    width: 100%;
    background: var(--surface);
    padding: 40px;
    border-radius: 20px;
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border);
}

.contact-form input,
.contact-form textarea {
    width: 100%;
    padding: 15px;
    margin-bottom: 20px;
    border: 2px solid var(--border);
    border-radius: 10px;
    font-size: 1rem;
    font-family: 'EB Garamond', serif;
    transition: all 0.3s ease;
    background: var(--background);
}

.contact-form input:focus,
.contact-form textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(114, 47, 55, 0.1);
    background: var(--surface);
}

.contact-form textarea {
    min-height: 150px;
    resize: vertical;
}

.contact-form button {
    width: 100%;
    padding: 15px;
    background: linear-gradient(135deg, var(--primary-gradient-start) 0%, var(--primary-gradient-end) 100%);
    color: white;
    border: none;
    border-radius: 10px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.contact-form button::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 50%;
    transform: translate(-50%, -50%);
    transition: width 0.6s, height 0.6s;
}

.contact-form button:hover::before {
    width: 300px;
    height: 300px;
}

.contact-form button:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(114, 47, 55, 0.3);
}

.contact-form button:active {
    transform: translateY(0);
}

/* Footer */
footer {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    height: 60px;
    background: var(--text-primary);
    color: white;
    text-align: center;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
}

footer p {
    opacity: 0.9;
}

/* Animations */
@keyframes fadeInDown {
    from {
        opacity: 0;
        transform: translateY(-30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Responsive Design */
@media (max-width: 1024px) {
    :root {
        --card-width: 300px;
    }
    
    .masonry-grid {
        column-count: 2;
    }
}

@media (max-width: 768px) {
    .hero h1 {
        font-size: 2.5rem;
    }

    .hero .tagline {
        font-size: 1.1rem;
    }

    nav ul {
        gap: 15px;
    }

    .section-header h2 {
        font-size: 2rem;
    }
    
    .masonry-grid {
        column-count: 1;
    }
    
    .regular-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 640px) {
    .hero {
        height: 180px;
    }
    
    nav {
        top: 180px;
        height: auto;
        min-height: 60px;
        padding: 10px;
    }
    
    .main-content {
        top: calc(180px + 60px);
    }
    
    nav ul {
        gap: 10px;
    }
    
    nav a {
        padding: 6px 12px;
        font-size: 0.85rem;
    }
}