/* ===================================
   CHEMISTRY ROADMAP - COMPLETE STYLES
   From Zero to Research Level
   =================================== */

/* CSS Variables */
:root {
    /* Primary Colors - Chemistry Inspired */
    --primary-dark: #0a1628;
    --primary-blue: #1a365d;
    --accent-teal: #00d4aa;
    --accent-cyan: #00b4d8;
    --accent-purple: #7c3aed;
    --accent-orange: #f97316;
    --accent-pink: #ec4899;
    --accent-yellow: #fbbf24;
    
    /* Background Colors */
    --bg-dark: #0f172a;
    --bg-medium: #1e293b;
    --bg-light: #334155;
    --bg-card: #1e3a5f;
    
    /* Text Colors */
    --text-white: #ffffff;
    --text-light: #e2e8f0;
    --text-muted: #94a3b8;
    
    /* Gradients */
    --gradient-main: linear-gradient(135deg, #0a1628 0%, #1a365d 50%, #0d4a6b 100%);
    --gradient-accent: linear-gradient(135deg, #00d4aa 0%, #00b4d8 100%);
    --gradient-purple: linear-gradient(135deg, #7c3aed 0%, #a855f7 100%);
    --gradient-warm: linear-gradient(135deg, #f97316 0%, #fbbf24 100%);
    
    /* Fonts */
    --font-display: 'Playfair Display', Georgia, serif;
    --font-body: 'Source Sans Pro', 'Segoe UI', sans-serif;
    --font-mono: 'JetBrains Mono', 'Consolas', monospace;
    
    /* Spacing */
    --section-padding: 80px;
    --content-max-width: 1400px;
}

/* Reset and Base Styles */
*, *::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: 600;
    background: var(--gradient-main);
    color: var(--text-light);
    line-height: 1.7;
    min-height: 100vh;
    overflow-x: hidden;
}

/* All text bold by default */
body, p, li, span, div {
    font-weight: 600;
}

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-display);
    font-weight: 800;
    color: var(--text-white);
}

/* ===================================
   PRINT BUTTON
   =================================== */
.print-btn {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 1000;
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 12px 24px;
    background: var(--gradient-accent);
    border: none;
    border-radius: 50px;
    color: var(--primary-dark);
    font-family: var(--font-body);
    font-size: 1rem;
    font-weight: 700;
    cursor: pointer;
    box-shadow: 0 4px 20px rgba(0, 212, 170, 0.4);
    transition: all 0.3s ease;
}

.print-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 30px rgba(0, 212, 170, 0.6);
}

.print-btn svg {
    width: 20px;
    height: 20px;
}

/* ===================================
   HEADER SECTION
   =================================== */
.main-header {
    position: relative;
    min-height: 500px;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 100px 20px;
    background: var(--gradient-main);
    overflow: hidden;
}

.molecule-bg {
    position: absolute;
    inset: 0;
    background-image: 
        radial-gradient(circle at 20% 30%, rgba(0, 212, 170, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 70%, rgba(124, 58, 237, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 50% 50%, rgba(0, 180, 216, 0.05) 0%, transparent 70%);
    animation: moleculeFloat 20s ease-in-out infinite;
}

@keyframes moleculeFloat {
    0%, 100% { transform: scale(1) rotate(0deg); }
    50% { transform: scale(1.1) rotate(5deg); }
}

.header-content {
    position: relative;
    z-index: 2;
    text-align: center;
    max-width: 900px;
}

/* Atom Animation */
.atom-icon {
    position: relative;
    width: 120px;
    height: 120px;
    margin: 0 auto 30px;
}

.nucleus {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 30px;
    height: 30px;
    background: var(--gradient-accent);
    border-radius: 50%;
    box-shadow: 0 0 30px rgba(0, 212, 170, 0.8);
}

.electron-orbit {
    position: absolute;
    top: 50%;
    left: 50%;
    border: 2px solid rgba(0, 212, 170, 0.3);
    border-radius: 50%;
    transform: translate(-50%, -50%);
}

.orbit-1 {
    width: 60px;
    height: 60px;
    animation: orbit1 3s linear infinite;
}

.orbit-2 {
    width: 90px;
    height: 90px;
    transform: translate(-50%, -50%) rotate(60deg);
    animation: orbit2 4s linear infinite;
}

.orbit-3 {
    width: 120px;
    height: 120px;
    transform: translate(-50%, -50%) rotate(-60deg);
    animation: orbit3 5s linear infinite;
}

.electron {
    position: absolute;
    width: 10px;
    height: 10px;
    background: var(--accent-cyan);
    border-radius: 50%;
    box-shadow: 0 0 15px rgba(0, 180, 216, 0.8);
    top: -5px;
    left: 50%;
    transform: translateX(-50%);
}

@keyframes orbit1 { from { transform: translate(-50%, -50%) rotate(0deg); } to { transform: translate(-50%, -50%) rotate(360deg); } }
@keyframes orbit2 { from { transform: translate(-50%, -50%) rotate(60deg); } to { transform: translate(-50%, -50%) rotate(420deg); } }
@keyframes orbit3 { from { transform: translate(-50%, -50%) rotate(-60deg); } to { transform: translate(-50%, -50%) rotate(300deg); } }

.main-header h1 {
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 900;
    letter-spacing: 4px;
    margin-bottom: 20px;
    background: var(--gradient-accent);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-shadow: none;
}

.subtitle {
    font-size: 1.4rem;
    font-weight: 700;
    color: var(--text-light);
    margin-bottom: 40px;
}

.header-stats {
    display: flex;
    justify-content: center;
    gap: 60px;
    flex-wrap: wrap;
}

.stat-item {
    text-align: center;
}

.stat-number {
    display: block;
    font-family: var(--font-display);
    font-size: 3rem;
    font-weight: 900;
    color: var(--accent-teal);
}

.stat-label {
    font-size: 1rem;
    font-weight: 700;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 2px;
}

/* ===================================
   STICKY NAVIGATION
   =================================== */
.sticky-nav {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(15, 23, 42, 0.95);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(0, 212, 170, 0.2);
    padding: 15px 20px;
    transition: all 0.3s ease;
}

.sticky-nav.scrolled {
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.3);
}

.nav-container {
    max-width: var(--content-max-width);
    margin: 0 auto;
}

.nav-title {
    font-weight: 700;
    color: var(--text-muted);
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 2px;
    margin-bottom: 12px;
}

.nav-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.nav-btn {
    padding: 8px 16px;
    background: var(--bg-light);
    border: 1px solid rgba(0, 212, 170, 0.3);
    border-radius: 25px;
    color: var(--text-light);
    font-family: var(--font-body);
    font-size: 0.9rem;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.3s ease;
}

.nav-btn:hover, .nav-btn.active {
    background: var(--accent-teal);
    color: var(--primary-dark);
    border-color: var(--accent-teal);
    transform: translateY(-2px);
}

.nav-btn.special {
    background: transparent;
    border-color: var(--accent-purple);
    color: var(--accent-purple);
}

.nav-btn.special:hover {
    background: var(--accent-purple);
    color: var(--text-white);
}

/* ===================================
   MAIN CONTENT
   =================================== */
.main-content {
    max-width: var(--content-max-width);
    margin: 0 auto;
    padding: 0 20px;
}

/* ===================================
   TABLE OF CONTENTS
   =================================== */
.toc-section {
    padding: var(--section-padding) 0;
}

.section-title {
    font-size: 2rem;
    font-weight: 800;
    margin-bottom: 40px;
    display: flex;
    align-items: center;
    gap: 15px;
}

.title-icon {
    font-size: 2.5rem;
}

.toc-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 20px;
}

.toc-card {
    display: flex;
    align-items: center;
    gap: 15px;
    padding: 20px 25px;
    background: var(--bg-card);
    border: 1px solid rgba(0, 212, 170, 0.2);
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.toc-card:hover {
    background: var(--bg-light);
    border-color: var(--accent-teal);
    transform: translateX(10px);
}

.toc-card.special {
    border-color: var(--accent-purple);
}

.toc-card.special:hover {
    border-color: var(--accent-pink);
}

.toc-number {
    font-family: var(--font-mono);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--accent-teal);
    min-width: 40px;
}

.toc-text {
    flex: 1;
    font-weight: 700;
    font-size: 1.1rem;
}

.toc-arrow {
    font-size: 1.5rem;
    color: var(--accent-teal);
    transition: transform 0.3s ease;
}

.toc-card:hover .toc-arrow {
    transform: translateX(5px);
}

/* ===================================
   STAGE SECTIONS
   =================================== */
.stage-section {
    padding: var(--section-padding) 0;
}

.stage-section.alt-bg {
    background: rgba(0, 0, 0, 0.2);
    margin: 0 -20px;
    padding-left: 20px;
    padding-right: 20px;
}

.stage-header {
    text-align: center;
    margin-bottom: 50px;
}

.stage-number {
    display: inline-block;
    padding: 8px 24px;
    background: var(--gradient-accent);
    color: var(--primary-dark);
    font-family: var(--font-mono);
    font-size: 0.9rem;
    font-weight: 700;
    letter-spacing: 3px;
    border-radius: 25px;
    margin-bottom: 20px;
}

.stage-title {
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 900;
    margin-bottom: 10px;
}

.stage-subtitle {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--text-muted);
}

/* Topic Groups */
.topic-group {
    margin-bottom: 40px;
    padding: 30px;
    background: var(--bg-card);
    border-radius: 16px;
    border-left: 4px solid var(--accent-teal);
}

.topic-group.wide {
    max-width: 100%;
}

.topic-heading {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 1.5rem;
    font-weight: 800;
    margin-bottom: 20px;
    color: var(--text-white);
}

.heading-icon {
    font-size: 1.8rem;
}

.sub-heading {
    font-size: 1.2rem;
    font-weight: 800;
    color: var(--accent-cyan);
    margin: 25px 0 15px 0;
    padding-bottom: 8px;
    border-bottom: 2px solid rgba(0, 180, 216, 0.3);
}

.topic-list {
    list-style: none;
    padding-left: 0;
}

.topic-list li {
    position: relative;
    padding: 12px 0 12px 30px;
    font-weight: 600;
    font-size: 1rem;
    color: var(--text-light);
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.topic-list li:last-child {
    border-bottom: none;
}

.topic-list li::before {
    content: '▸';
    position: absolute;
    left: 0;
    color: var(--accent-teal);
    font-size: 1.2rem;
    font-weight: 700;
}

.topic-list li strong {
    color: var(--text-white);
    font-weight: 800;
}

/* Branch Container */
.branch-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 30px;
}

.branch-card {
    padding: 30px;
    background: var(--bg-card);
    border-radius: 16px;
    border-top: 4px solid var(--accent-teal);
}

.branch-card.full-width {
    grid-column: 1 / -1;
}

.branch-title {
    font-size: 1.6rem;
    font-weight: 800;
    margin-bottom: 25px;
    color: var(--text-white);
}

.topic-columns {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
}

/* Specialization Grid */
.specialization-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 25px;
}

.spec-card {
    padding: 30px;
    background: var(--bg-card);
    border-radius: 16px;
    border: 1px solid rgba(0, 212, 170, 0.2);
    transition: all 0.3s ease;
}

.spec-card:hover {
    border-color: var(--accent-teal);
    transform: translateY(-5px);
    box-shadow: 0 10px 40px rgba(0, 212, 170, 0.1);
}

.spec-icon {
    font-size: 3rem;
    margin-bottom: 20px;
}

.spec-card h4 {
    font-size: 1.3rem;
    font-weight: 800;
    margin-bottom: 20px;
    color: var(--accent-cyan);
}

/* PhD Timeline */
.phd-timeline {
    position: relative;
    padding-left: 40px;
}

.phd-timeline::before {
    content: '';
    position: absolute;
    left: 15px;
    top: 0;
    bottom: 0;
    width: 3px;
    background: var(--gradient-accent);
    border-radius: 3px;
}

.timeline-item {
    position: relative;
    margin-bottom: 40px;
    padding: 25px;
    background: var(--bg-card);
    border-radius: 16px;
}

.timeline-marker {
    position: absolute;
    left: -55px;
    top: 25px;
    width: 40px;
    text-align: center;
    font-family: var(--font-mono);
    font-size: 0.75rem;
    font-weight: 700;
    color: var(--accent-teal);
    background: var(--bg-dark);
    padding: 5px;
    border-radius: 5px;
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: -25px;
    top: 30px;
    width: 12px;
    height: 12px;
    background: var(--accent-teal);
    border-radius: 50%;
    box-shadow: 0 0 15px rgba(0, 212, 170, 0.6);
}

.timeline-content h4 {
    font-size: 1.4rem;
    font-weight: 800;
    margin-bottom: 15px;
    color: var(--text-white);
}

/* Research Areas Grid */
.research-areas-grid {
    margin-top: 50px;
    padding: 40px;
    background: var(--bg-card);
    border-radius: 16px;
}

.topic-heading.centered {
    justify-content: center;
    text-align: center;
}

.research-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 15px;
    margin-top: 30px;
}

.research-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 15px 20px;
    background: var(--bg-light);
    border-radius: 10px;
    font-weight: 700;
    transition: all 0.3s ease;
}

.research-item:hover {
    background: var(--accent-teal);
    color: var(--primary-dark);
    transform: scale(1.02);
}

.research-icon {
    font-size: 1.5rem;
}

/* PostDoc Grid */
.postdoc-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 25px;
}

.postdoc-card {
    padding: 30px;
    background: var(--bg-card);
    border-radius: 16px;
    border-left: 4px solid var(--accent-purple);
}

.postdoc-card h4 {
    font-size: 1.3rem;
    font-weight: 800;
    margin-bottom: 20px;
    color: var(--accent-purple);
}

/* Advanced Grid */
.advanced-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 25px;
    margin-bottom: 50px;
}

.advanced-card {
    padding: 30px;
    background: var(--bg-card);
    border-radius: 16px;
    border-top: 4px solid var(--accent-orange);
}

.advanced-card h4 {
    font-size: 1.3rem;
    font-weight: 800;
    margin-bottom: 20px;
    color: var(--accent-orange);
}

/* Frontier Section */
.frontier-section {
    padding: 40px;
    background: linear-gradient(135deg, rgba(124, 58, 237, 0.2) 0%, rgba(236, 72, 153, 0.1) 100%);
    border-radius: 16px;
    border: 1px solid rgba(124, 58, 237, 0.3);
}

.frontier-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 20px;
    margin-top: 30px;
}

.frontier-item {
    padding: 25px;
    background: rgba(0, 0, 0, 0.3);
    border-radius: 12px;
    border-left: 3px solid var(--accent-pink);
}

.frontier-item h5 {
    font-size: 1.1rem;
    font-weight: 800;
    margin-bottom: 10px;
    color: var(--accent-pink);
}

.frontier-item p {
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--text-muted);
}

/* ===================================
   FLOWCHART SECTION
   =================================== */
.visual-section {
    padding: var(--section-padding) 0;
    margin: 50px 0;
}

.section-header {
    text-align: center;
    margin-bottom: 50px;
}

.visual-title {
    font-size: clamp(1.8rem, 3vw, 2.5rem);
    font-weight: 900;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 15px;
    margin-bottom: 15px;
}

.visual-subtitle {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--text-muted);
}

.flowchart-container {
    padding: 40px;
    background: var(--bg-card);
    border-radius: 20px;
    border: 1px solid rgba(0, 212, 170, 0.2);
    overflow-x: auto;
}

.flowchart {
    min-width: 800px;
    padding: 30px;
}

.flow-row {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 20px;
    margin-bottom: 10px;
}

.flow-row.reverse {
    flex-direction: row-reverse;
}

.flow-row.vertical-connector {
    justify-content: flex-end;
    padding-right: 100px;
}

.vertical-spacer {
    width: 150px;
}

.flow-node {
    width: 150px;
    padding: 20px;
    background: var(--bg-light);
    border: 2px solid var(--accent-teal);
    border-radius: 15px;
    text-align: center;
    transition: all 0.3s ease;
}

.flow-node:hover {
    transform: scale(1.05);
    box-shadow: 0 0 30px rgba(0, 212, 170, 0.3);
}

.flow-node.start {
    border-color: var(--accent-yellow);
    background: linear-gradient(135deg, rgba(251, 191, 36, 0.2) 0%, rgba(249, 115, 22, 0.1) 100%);
}

.flow-node.end {
    border-color: var(--accent-pink);
    background: linear-gradient(135deg, rgba(236, 72, 153, 0.2) 0%, rgba(124, 58, 237, 0.1) 100%);
}

.node-content {
    display: flex;
    flex-direction: column;
    gap: 5px;
}

.node-icon {
    font-size: 2rem;
}

.node-title {
    font-size: 1.1rem;
    font-weight: 800;
    color: var(--text-white);
}

.node-desc {
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--text-muted);
}

.flow-arrow {
    width: 60px;
    height: 20px;
}

.flow-arrow.vertical {
    width: 20px;
    height: 50px;
}

.flow-arrow svg {
    width: 100%;
    height: 100%;
}

/* Branch Paths */
.branch-paths {
    margin-top: 50px;
    padding-top: 30px;
    border-top: 2px dashed rgba(0, 212, 170, 0.3);
}

.branch-title {
    text-align: center;
    font-size: 1.2rem;
    font-weight: 800;
    color: var(--accent-cyan);
    margin-bottom: 25px;
}

.branch-row {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 15px;
}

.branch-node {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 12px 20px;
    background: var(--bg-medium);
    border: 1px solid rgba(0, 180, 216, 0.3);
    border-radius: 10px;
    font-weight: 700;
    transition: all 0.3s ease;
}

.branch-node:hover {
    background: var(--accent-cyan);
    color: var(--primary-dark);
}

.branch-icon {
    font-size: 1.3rem;
}

/* ===================================
   MIND MAP SECTION
   =================================== */
.mindmap-bg {
    background: linear-gradient(180deg, rgba(0, 0, 0, 0.2) 0%, transparent 100%);
    padding-top: 60px;
    padding-bottom: 60px;
}

.mindmap-container {
    padding: 60px 40px;
    background: var(--bg-card);
    border-radius: 20px;
    border: 1px solid rgba(124, 58, 237, 0.2);
    overflow-x: auto;
}

.mindmap {
    position: relative;
    min-width: 1000px;
    min-height: 700px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.mindmap-center {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    z-index: 10;
}

.center-node {
    width: 140px;
    height: 140px;
    background: var(--gradient-accent);
    border-radius: 50%;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    box-shadow: 0 0 50px rgba(0, 212, 170, 0.5);
}

.center-icon {
    font-size: 3rem;
}

.center-text {
    font-family: var(--font-display);
    font-size: 1rem;
    font-weight: 900;
    color: var(--primary-dark);
    margin-top: 5px;
}

/* Mind Map Branches */
.mindmap-branch {
    position: absolute;
}

.branch-connector {
    position: absolute;
    width: 100px;
    height: 3px;
    background: linear-gradient(90deg, var(--accent-teal) 0%, transparent 100%);
}

.main-branch {
    padding: 15px 25px;
    border-radius: 25px;
    font-weight: 800;
    font-size: 1rem;
    white-space: nowrap;
}

.main-branch.physical { background: linear-gradient(135deg, #3b82f6 0%, #1d4ed8 100%); }
.main-branch.organic { background: linear-gradient(135deg, #22c55e 0%, #16a34a 100%); }
.main-branch.inorganic { background: linear-gradient(135deg, #f97316 0%, #ea580c 100%); }
.main-branch.analytical { background: linear-gradient(135deg, #8b5cf6 0%, #7c3aed 100%); }
.main-branch.biochem { background: linear-gradient(135deg, #ec4899 0%, #db2777 100%); }
.main-branch.applied { background: linear-gradient(135deg, #06b6d4 0%, #0891b2 100%); }

.sub-branches {
    display: flex;
    flex-direction: column;
    gap: 8px;
    margin-top: 15px;
}

.sub-branch {
    padding: 8px 15px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 15px;
    font-size: 0.85rem;
    font-weight: 700;
    white-space: nowrap;
}

/* Branch Positions */
.branch-1 { top: 50px; left: 50%; transform: translateX(-50%); }
.branch-1 .branch-connector { display: none; }
.branch-1 .sub-branches { flex-direction: row; flex-wrap: wrap; justify-content: center; }

.branch-2 { top: 200px; right: 50px; }
.branch-2 .connector-2 { left: -100px; top: 25px; }
.branch-2 .sub-branches { align-items: flex-end; }

.branch-3 { top: 400px; right: 50px; }
.branch-3 .connector-3 { left: -100px; top: 25px; }
.branch-3 .sub-branches { align-items: flex-end; }

.branch-4 { bottom: 50px; left: 50%; transform: translateX(-50%); }
.branch-4 .branch-connector { display: none; }
.branch-4 .sub-branches { flex-direction: row; flex-wrap: wrap; justify-content: center; }

.branch-5 { top: 200px; left: 50px; }
.branch-5 .connector-5 { right: -100px; top: 25px; transform: rotate(180deg); }

.branch-6 { top: 400px; left: 50px; }
.branch-6 .connector-6 { right: -100px; top: 25px; transform: rotate(180deg); }

/* ===================================
   VISUAL ROADMAP SECTION
   =================================== */
.roadmap-bg {
    background: linear-gradient(180deg, transparent 0%, rgba(0, 0, 0, 0.2) 100%);
}

.roadmap-container {
    padding: 50px 40px;
    background: var(--bg-card);
    border-radius: 20px;
    border: 1px solid rgba(249, 115, 22, 0.2);
}

.roadmap-visual {
    position: relative;
}

.roadmap-track {
    position: relative;
    padding: 40px 0;
}

.track-line {
    position: absolute;
    top: 80px;
    left: 0;
    right: 0;
    height: 6px;
    background: linear-gradient(90deg, 
        var(--accent-yellow) 0%, 
        var(--accent-teal) 25%, 
        var(--accent-cyan) 50%, 
        var(--accent-purple) 75%, 
        var(--accent-pink) 100%
    );
    border-radius: 3px;
}

.roadmap-stop {
    position: relative;
    display: inline-block;
    width: calc(16.66% - 20px);
    margin: 0 10px;
    vertical-align: top;
}

.stop-marker {
    width: 60px;
    height: 60px;
    margin: 0 auto 20px;
    background: var(--bg-dark);
    border: 4px solid var(--accent-teal);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    z-index: 2;
}

.stop-marker.final {
    background: var(--gradient-warm);
    border-color: var(--accent-orange);
}

.stop-number {
    font-family: var(--font-mono);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--accent-teal);
}

.stop-marker.final .stop-number {
    color: var(--text-white);
}

.stop-content {
    text-align: center;
    padding-top: 20px;
}

.stop-content h4 {
    font-size: 1.1rem;
    font-weight: 800;
    margin-bottom: 5px;
}

.stop-content p {
    font-size: 0.9rem;
    font-weight: 700;
    color: var(--text-muted);
    margin-bottom: 15px;
}

.stop-topics {
    list-style: none;
    text-align: center;
}

.stop-topics li {
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--text-light);
    padding: 4px 0;
}

/* Skills Progress */
.skills-progress {
    margin-top: 60px;
    padding: 30px;
    background: var(--bg-light);
    border-radius: 15px;
}

.skills-title {
    font-size: 1.3rem;
    font-weight: 800;
    margin-bottom: 25px;
    text-align: center;
    color: var(--text-white);
}

.skill-bar {
    margin-bottom: 20px;
}

.skill-name {
    display: block;
    font-weight: 700;
    margin-bottom: 8px;
    color: var(--text-light);
}

.progress-track {
    height: 12px;
    background: var(--bg-dark);
    border-radius: 6px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: var(--gradient-accent);
    border-radius: 6px;
    transition: width 1s ease;
}

/* ===================================
   DISCLAIMER SECTION
   =================================== */
.disclaimer-section {
    padding: var(--section-padding) 0;
}

.disclaimer-box {
    max-width: 900px;
    margin: 0 auto;
    padding: 40px;
    background: linear-gradient(135deg, rgba(251, 191, 36, 0.1) 0%, rgba(249, 115, 22, 0.05) 100%);
    border: 2px solid var(--accent-yellow);
    border-radius: 16px;
    text-align: center;
}

.disclaimer-icon {
    font-size: 3rem;
    margin-bottom: 20px;
}

.disclaimer-box h3 {
    font-size: 1.8rem;
    font-weight: 900;
    margin-bottom: 20px;
    color: var(--accent-yellow);
}

.disclaimer-box p {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-light);
    margin-bottom: 15px;
    line-height: 1.8;
}

.disclaimer-footer {
    margin-top: 25px;
    padding-top: 20px;
    border-top: 1px solid rgba(251, 191, 36, 0.3);
    font-weight: 700;
    color: var(--text-muted);
}

/* ===================================
   BACK TO TOP BUTTON
   =================================== */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--gradient-purple);
    border: none;
    border-radius: 50%;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    z-index: 1000;
    box-shadow: 0 4px 20px rgba(124, 58, 237, 0.4);
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    transform: translateY(-5px);
    box-shadow: 0 6px 30px rgba(124, 58, 237, 0.6);
}

.back-to-top svg {
    width: 24px;
    height: 24px;
    color: var(--text-white);
}

/* ===================================
   FOOTER
   =================================== */
.main-footer {
    background: var(--bg-dark);
    padding: 50px 20px;
    text-align: center;
    border-top: 1px solid rgba(0, 212, 170, 0.2);
}

.footer-logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    font-family: var(--font-display);
    font-size: 1.5rem;
    font-weight: 800;
    margin-bottom: 15px;
}

.footer-icon {
    font-size: 2rem;
}

.footer-text {
    font-weight: 700;
    color: var(--text-muted);
    margin-bottom: 10px;
}

.footer-copyright {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-muted);
}

/* ===================================
   RESPONSIVE DESIGN
   =================================== */
@media (max-width: 1200px) {
    .mindmap {
        min-width: 800px;
    }
    
    .roadmap-stop {
        width: calc(33.33% - 20px);
        margin-bottom: 40px;
    }
}

@media (max-width: 992px) {
    .branch-container {
        grid-template-columns: 1fr;
    }
    
    .specialization-grid {
        grid-template-columns: 1fr;
    }
    
    .header-stats {
        gap: 30px;
    }
}

@media (max-width: 768px) {
    :root {
        --section-padding: 50px;
    }
    
    .print-btn {
        top: 10px;
        right: 10px;
        padding: 10px 16px;
        font-size: 0.9rem;
    }
    
    .print-btn span {
        display: none;
    }
    
    .nav-buttons {
        gap: 8px;
    }
    
    .nav-btn {
        padding: 6px 12px;
        font-size: 0.8rem;
    }
    
    .toc-grid {
        grid-template-columns: 1fr;
    }
    
    .flow-row {
        flex-wrap: wrap;
    }
    
    .flow-node {
        width: 120px;
        padding: 15px;
    }
    
    .roadmap-stop {
        width: calc(50% - 20px);
    }
    
    .phd-timeline {
        padding-left: 30px;
    }
    
    .timeline-marker {
        left: -45px;
        font-size: 0.65rem;
        width: 35px;
    }
}

@media (max-width: 576px) {
    .main-header {
        min-height: 400px;
        padding: 80px 15px;
    }
    
    .atom-icon {
        width: 80px;
        height: 80px;
    }
    
    .nucleus {
        width: 20px;
        height: 20px;
    }
    
    .orbit-1 { width: 40px; height: 40px; }
    .orbit-2 { width: 60px; height: 60px; }
    .orbit-3 { width: 80px; height: 80px; }
    
    .electron {
        width: 8px;
        height: 8px;
        top: -4px;
    }
    
    .topic-group {
        padding: 20px;
    }
    
    .roadmap-stop {
        width: 100%;
    }
    
    .branch-row {
        flex-direction: column;
    }
    
    .branch-node {
        width: 100%;
        justify-content: center;
    }
}

/* ===================================
   PRINT STYLES
   =================================== */
@media print {
    * {
        -webkit-print-color-adjust: exact !important;
        print-color-adjust: exact !important;
        color-adjust: exact !important;
    }
    
    body {
        background: white !important;
        color: #1a1a1a !important;
        font-size: 11pt;
    }
    
    .print-btn,
    .sticky-nav,
    .back-to-top,
    .atom-icon,
    .molecule-bg {
        display: none !important;
    }
    
    .main-header {
        background: #f0f0f0 !important;
        min-height: auto;
        padding: 30px;
        page-break-after: avoid;
    }
    
    .main-header h1 {
        color: #0a1628 !important;
        -webkit-text-fill-color: #0a1628 !important;
        background: none !important;
        font-size: 24pt;
    }
    
    .subtitle, .stat-label {
        color: #444 !important;
    }
    
    .stat-number {
        color: #00796b !important;
    }
    
    .stage-section,
    .visual-section,
    .disclaimer-section {
        page-break-inside: avoid;
        padding: 20px 0;
    }
    
    .stage-section.alt-bg {
        background: #f5f5f5 !important;
        margin: 0;
    }
    
    .stage-number {
        background: #00796b !important;
        color: white !important;
    }
    
    .stage-title,
    .visual-title,
    .topic-heading,
    .branch-title,
    h3, h4, h5 {
        color: #1a1a1a !important;
    }
    
    .topic-group,
    .branch-card,
    .spec-card,
    .postdoc-card,
    .advanced-card,
    .flowchart-container,
    .mindmap-container,
    .roadmap-container,
    .disclaimer-box {
        background: #f9f9f9 !important;
        border: 1px solid #ddd !important;
        box-shadow: none !important;
    }
    
    .topic-list li {
        color: #333 !important;
        border-bottom-color: #eee !important;
    }
    
    .topic-list li strong {
        color: #1a1a1a !important;
    }
    
    .topic-list li::before {
        color: #00796b !important;
    }
    
    .sub-heading {
        color: #00796b !important;
        border-bottom-color: #00796b !important;
    }
    
    .toc-section {
        display: none;
    }
    
    .flow-node {
        background: white !important;
        border-color: #00796b !important;
    }
    
    .node-title, .stop-content h4 {
        color: #1a1a1a !important;
    }
    
    .node-desc, .stop-content p {
        color: #666 !important;
    }
    
    .main-footer {
        background: #f0f0f0 !important;
        border-top: 1px solid #ddd !important;
    }
    
    .footer-logo, .footer-text, .footer-copyright {
        color: #333 !important;
    }
    
    a {
        text-decoration: none;
        color: #00796b !important;
    }
    
    .mindmap-container,
    .flowchart-container {
        overflow: visible;
        page-break-inside: avoid;
    }
    
    .disclaimer-box {
        border-color: #f0ad4e !important;
    }
    
    .disclaimer-box h3 {
        color: #c87800 !important;
    }
}