/* ========================================
   PHYSICS ROADMAP - COMPLETE STYLESHEET
   ======================================== */

/* CSS Variables */
:root {
    --primary-bg: #0a1628;
    --secondary-bg: #112240;
    --tertiary-bg: #1d3557;
    --accent-blue: #4fc3f7;
    --accent-cyan: #00bcd4;
    --accent-green: #4caf50;
    --accent-orange: #ff9800;
    --accent-purple: #ab47bc;
    --accent-red: #ef5350;
    --accent-yellow: #ffd54f;
    --text-primary: #ffffff;
    --text-secondary: #b0bec5;
    --text-dark: #1a1a2e;
    --shadow-color: rgba(0, 0, 0, 0.3);
    --glow-blue: rgba(79, 195, 247, 0.4);
    --stage1-color: #4fc3f7;
    --stage2-color: #4caf50;
    --stage3-color: #ff9800;
    --stage4-color: #ab47bc;
    --stage5-color: #ef5350;
    --stage6-color: #ffd54f;
}

/* Reset & Base */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Poppins', sans-serif;
    background: var(--primary-bg);
    color: var(--text-primary);
    line-height: 1.8;
    min-height: 100vh;
}

/* ========================================
   HEADER STYLES
   ======================================== */
.main-header {
    background: linear-gradient(135deg, var(--secondary-bg) 0%, var(--tertiary-bg) 50%, var(--secondary-bg) 100%);
    padding: 60px 20px;
    text-align: center;
    border-bottom: 3px solid var(--accent-cyan);
    position: relative;
    overflow: hidden;
}

.main-header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        radial-gradient(circle at 20% 80%, rgba(79, 195, 247, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(171, 71, 188, 0.1) 0%, transparent 50%);
    pointer-events: none;
}

.header-content {
    position: relative;
    z-index: 1;
}

.main-header h1 {
    font-family: 'Montserrat', sans-serif;
    font-size: 3.2rem;
    font-weight: 800;
    color: var(--text-primary);
    text-shadow: 0 0 30px var(--glow-blue);
    margin-bottom: 15px;
    letter-spacing: 2px;
}

.main-header .subtitle {
    font-size: 1.4rem;
    font-weight: 600;
    color: var(--accent-cyan);
    margin-bottom: 30px;
}

.print-btn {
    background: linear-gradient(135deg, var(--accent-cyan), var(--accent-blue));
    color: var(--text-dark);
    border: none;
    padding: 15px 40px;
    font-size: 1.1rem;
    font-weight: 700;
    border-radius: 50px;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 5px 20px rgba(79, 195, 247, 0.4);
}

.print-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 30px rgba(79, 195, 247, 0.6);
}

/* ========================================
   NAVIGATION STYLES
   ======================================== */
.quick-nav {
    background: var(--secondary-bg);
    padding: 30px 20px;
    text-align: center;
    position: sticky;
    top: 0;
    z-index: 1000;
    border-bottom: 2px solid var(--tertiary-bg);
    box-shadow: 0 5px 20px var(--shadow-color);
}

.quick-nav h3 {
    font-family: 'Montserrat', sans-serif;
    font-weight: 700;
    color: var(--accent-cyan);
    margin-bottom: 20px;
    font-size: 1.3rem;
}

.nav-buttons {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 12px;
    max-width: 1400px;
    margin: 0 auto;
}

.nav-btn {
    background: var(--tertiary-bg);
    color: var(--text-primary);
    border: 2px solid var(--accent-cyan);
    padding: 12px 24px;
    font-size: 0.95rem;
    font-weight: 600;
    border-radius: 30px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.nav-btn:hover {
    background: var(--accent-cyan);
    color: var(--text-dark);
    transform: translateY(-2px);
    box-shadow: 0 5px 15px var(--glow-blue);
}

/* ========================================
   MAIN CONTENT WRAPPER
   ======================================== */
.content-wrapper {
    max-width: 1400px;
    margin: 0 auto;
    padding: 40px 20px;
}

/* ========================================
   STAGE SECTION STYLES
   ======================================== */
.stage-section {
    background: var(--secondary-bg);
    border-radius: 20px;
    margin-bottom: 40px;
    overflow: hidden;
    box-shadow: 0 10px 40px var(--shadow-color);
    border: 1px solid var(--tertiary-bg);
}

.stage-header {
    padding: 30px 40px;
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 20px;
    position: relative;
}

#stage1 .stage-header { background: linear-gradient(135deg, rgba(79, 195, 247, 0.2), rgba(79, 195, 247, 0.05)); border-left: 5px solid var(--stage1-color); }
#stage2 .stage-header { background: linear-gradient(135deg, rgba(76, 175, 80, 0.2), rgba(76, 175, 80, 0.05)); border-left: 5px solid var(--stage2-color); }
#stage3 .stage-header { background: linear-gradient(135deg, rgba(255, 152, 0, 0.2), rgba(255, 152, 0, 0.05)); border-left: 5px solid var(--stage3-color); }
#stage4 .stage-header { background: linear-gradient(135deg, rgba(171, 71, 188, 0.2), rgba(171, 71, 188, 0.05)); border-left: 5px solid var(--stage4-color); }
#stage5 .stage-header { background: linear-gradient(135deg, rgba(239, 83, 80, 0.2), rgba(239, 83, 80, 0.05)); border-left: 5px solid var(--stage5-color); }
#stage6 .stage-header { background: linear-gradient(135deg, rgba(255, 213, 79, 0.2), rgba(255, 213, 79, 0.05)); border-left: 5px solid var(--stage6-color); }

.stage-number {
    font-family: 'Montserrat', sans-serif;
    font-size: 2.5rem;
    font-weight: 800;
    opacity: 0.3;
}

#stage1 .stage-number { color: var(--stage1-color); }
#stage2 .stage-number { color: var(--stage2-color); }
#stage3 .stage-number { color: var(--stage3-color); }
#stage4 .stage-number { color: var(--stage4-color); }
#stage5 .stage-number { color: var(--stage5-color); }
#stage6 .stage-number { color: var(--stage6-color); }

.stage-header h2 {
    font-family: 'Montserrat', sans-serif;
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--text-primary);
    flex: 1;
}

.duration {
    background: var(--tertiary-bg);
    padding: 8px 20px;
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--accent-cyan);
}

.stage-content {
    padding: 30px 40px;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 30px;
}

/* ========================================
   TOPIC GROUP STYLES
   ======================================== */
.topic-group {
    background: var(--tertiary-bg);
    border-radius: 15px;
    padding: 25px;
    transition: all 0.3s ease;
}

.topic-group:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px var(--shadow-color);
}

.topic-group h3 {
    font-family: 'Montserrat', sans-serif;
    font-size: 1.2rem;
    font-weight: 700;
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 2px solid var(--accent-cyan);
    color: var(--accent-cyan);
}

.topic-group ul {
    list-style: none;
}

.topic-group li {
    padding: 12px 0;
    padding-left: 25px;
    position: relative;
    font-size: 1rem;
    font-weight: 500;
    color: var(--text-primary);
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

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

.topic-group li::before {
    content: '▸';
    position: absolute;
    left: 0;
    color: var(--accent-cyan);
    font-weight: bold;
}

.topic-group li strong {
    color: var(--accent-yellow);
    font-weight: 700;
}

/* Specialization styling */
.topic-group.specialization {
    border: 2px solid var(--stage5-color);
}

.topic-group.specialization h3 {
    color: var(--stage5-color);
    border-color: var(--stage5-color);
}

.topic-group.specialization li::before {
    color: var(--stage5-color);
}

/* Research styling */
.topic-group.research {
    border: 2px solid var(--stage6-color);
}

.topic-group.research h3 {
    color: var(--stage6-color);
    border-color: var(--stage6-color);
}

.topic-group.research li::before {
    color: var(--stage6-color);
}

/* ========================================
   VISUAL SECTIONS (Flowchart, Mind Map, Roadmap)
   ======================================== */
.visual-section {
    background: var(--secondary-bg);
    border-radius: 20px;
    padding: 40px;
    margin-bottom: 40px;
    box-shadow: 0 10px 40px var(--shadow-color);
    border: 1px solid var(--tertiary-bg);
}

.visual-section h2 {
    font-family: 'Montserrat', sans-serif;
    font-size: 2rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 40px;
    color: var(--accent-cyan);
}

/* ========================================
   FLOWCHART STYLES
   ======================================== */
.flowchart-container {
    overflow-x: auto;
    padding: 20px;
}

.flowchart {
    display: flex;
    flex-direction: column;
    align-items: center;
    min-width: 600px;
    padding: 30px;
}

.flow-box {
    padding: 20px 40px;
    border-radius: 15px;
    text-align: center;
    font-weight: 700;
    min-width: 280px;
    box-shadow: 0 5px 20px var(--shadow-color);
}

.flow-box strong {
    display: block;
    font-size: 1.1rem;
    margin-bottom: 5px;
}

.flow-box span {
    font-size: 0.85rem;
    font-weight: 500;
    opacity: 0.9;
}

.flow-box.start {
    background: linear-gradient(135deg, #2ecc71, #27ae60);
    color: white;
    font-size: 1.2rem;
}

.flow-box.end {
    background: linear-gradient(135deg, #e74c3c, #c0392b);
    color: white;
    font-size: 1.2rem;
}

.stage1-flow {
    background: linear-gradient(135deg, var(--stage1-color), #0288d1);
    color: var(--text-dark);
}

.stage2-flow {
    background: linear-gradient(135deg, var(--stage2-color), #388e3c);
    color: white;
}

.stage3-flow {
    background: linear-gradient(135deg, var(--stage3-color), #f57c00);
    color: var(--text-dark);
}

.stage4-flow {
    background: linear-gradient(135deg, var(--stage4-color), #8e24aa);
    color: white;
}

.spec-flow {
    background: linear-gradient(135deg, var(--stage5-color), #d32f2f);
    color: white;
    padding: 15px 20px;
    min-width: 140px;
    font-size: 0.9rem;
}

.research-flow {
    background: linear-gradient(135deg, var(--stage6-color), #ffc107);
    color: var(--text-dark);
}

.flow-diamond {
    width: 140px;
    height: 140px;
    background: linear-gradient(135deg, #9b59b6, #8e44ad);
    transform: rotate(45deg);
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 5px 20px var(--shadow-color);
}

.flow-diamond span {
    transform: rotate(-45deg);
    font-weight: 700;
    color: white;
    font-size: 0.95rem;
    text-align: center;
}

.arrow-down {
    width: 4px;
    height: 50px;
    background: var(--accent-cyan);
    position: relative;
    margin: 5px 0;
}

.arrow-down::after {
    content: '';
    position: absolute;
    bottom: -12px;
    left: 50%;
    transform: translateX(-50%);
    border-left: 12px solid transparent;
    border-right: 12px solid transparent;
    border-top: 15px solid var(--accent-cyan);
}

.arrow-down.merge {
    height: 30px;
}

.flow-branch {
    width: 100%;
    max-width: 700px;
    position: relative;
    height: 30px;
    margin: 10px 0;
}

.branch-line {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--accent-cyan);
}

.branch-line::before,
.branch-line::after {
    content: '';
    position: absolute;
    width: 4px;
    height: 30px;
    background: var(--accent-cyan);
}

.branch-line::before {
    left: 0;
}

.branch-line::after {
    right: 0;
}

.specialization-boxes {
    display: flex;
    gap: 15px;
    flex-wrap: wrap;
    justify-content: center;
    margin: 10px 0;
}

/* ========================================
   MIND MAP STYLES
   ======================================== */
.mindmap-container {
    overflow-x: auto;
    padding: 20px;
}

.mindmap-svg {
    width: 100%;
    max-width: 1200px;
    height: auto;
    min-height: 500px;
    display: block;
    margin: 0 auto;
}

.center-node {
    fill: linear-gradient(135deg, var(--accent-cyan), var(--accent-blue));
    fill: var(--accent-cyan);
    stroke: var(--text-primary);
    stroke-width: 3;
    filter: drop-shadow(0 0 20px var(--glow-blue));
}

.center-text {
    fill: var(--text-dark);
    font-family: 'Montserrat', sans-serif;
    font-size: 18px;
    font-weight: 800;
    text-anchor: middle;
}

.branch-line {
    stroke-width: 4;
    fill: none;
}

.branch1 { stroke: var(--stage2-color); }
.branch2 { stroke: var(--stage3-color); }
.branch3 { stroke: var(--stage1-color); }
.branch4 { stroke: var(--stage4-color); }
.branch5 { stroke: var(--stage5-color); }
.branch6 { stroke: var(--stage6-color); }

.branch-node {
    stroke: var(--text-primary);
    stroke-width: 2;
}

.branch1-node { fill: var(--stage2-color); }
.branch2-node { fill: var(--stage3-color); }
.branch3-node { fill: var(--stage1-color); }
.branch4-node { fill: var(--stage4-color); }
.branch5-node { fill: var(--stage5-color); }
.branch6-node { fill: var(--stage6-color); }

.branch-text {
    fill: var(--text-dark);
    font-family: 'Montserrat', sans-serif;
    font-size: 12px;
    font-weight: 700;
    text-anchor: middle;
}

.sub-branch {
    stroke: var(--text-secondary);
    stroke-width: 2;
    fill: none;
}

.sub-node {
    stroke: var(--text-primary);
    stroke-width: 1;
}

.sub1 { fill: rgba(76, 175, 80, 0.8); }
.sub2 { fill: rgba(255, 152, 0, 0.8); }
.sub3 { fill: rgba(79, 195, 247, 0.8); }
.sub4 { fill: rgba(171, 71, 188, 0.8); }
.sub5 { fill: rgba(239, 83, 80, 0.8); }
.sub6 { fill: rgba(255, 213, 79, 0.8); }

.sub-text {
    fill: var(--text-dark);
    font-family: 'Poppins', sans-serif;
    font-size: 11px;
    font-weight: 600;
    text-anchor: middle;
}

/* ========================================
   VISUAL ROADMAP STYLES
   ======================================== */
.roadmap-container {
    padding: 40px 20px;
    overflow-x: auto;
}

.roadmap-track {
    position: relative;
    min-height: 800px;
    max-width: 900px;
    margin: 0 auto;
    padding: 20px 0;
}

.timeline-line {
    position: absolute;
    left: 50%;
    top: 0;
    bottom: 0;
    width: 6px;
    background: linear-gradient(
        to bottom,
        var(--stage1-color) 0%,
        var(--stage2-color) 20%,
        var(--stage3-color) 40%,
        var(--stage4-color) 55%,
        var(--stage5-color) 75%,
        var(--stage6-color) 90%,
        #e74c3c 100%
    );
    transform: translateX(-50%);
    border-radius: 3px;
}

.milestone {
    position: absolute;
    left: 50%;
    top: calc(var(--position) * 0.85 + 5%);
    transform: translateX(-50%);
    display: flex;
    align-items: center;
    width: 100%;
}

.milestone-marker {
    width: 30px;
    height: 30px;
    border-radius: 50%;
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    z-index: 10;
    border: 4px solid var(--text-primary);
    box-shadow: 0 0 20px var(--glow-blue);
}

.start-marker { background: #2ecc71; }
.math-marker { background: var(--stage1-color); }
.classical-marker { background: var(--stage2-color); }
.modern-marker { background: var(--stage3-color); }
.advanced-marker { background: var(--stage4-color); }
.spec-marker { background: var(--stage5-color); }
.research-marker { background: var(--stage6-color); }
.end-marker { background: #e74c3c; }

.milestone-content {
    background: var(--tertiary-bg);
    padding: 20px 25px;
    border-radius: 15px;
    max-width: 320px;
    position: absolute;
    box-shadow: 0 5px 20px var(--shadow-color);
    border: 2px solid var(--accent-cyan);
}

.milestone-content.left {
    right: calc(50% + 40px);
    text-align: right;
}

.milestone-content.right {
    left: calc(50% + 40px);
    text-align: left;
}

.milestone-content h4 {
    font-family: 'Montserrat', sans-serif;
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--accent-cyan);
    margin-bottom: 8px;
}

.milestone-content p {
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--text-secondary);
    margin-bottom: 10px;
}

.time-tag {
    display: inline-block;
    background: var(--accent-cyan);
    color: var(--text-dark);
    padding: 5px 15px;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 700;
}

/* ========================================
   DISCLAIMER STYLES
   ======================================== */
.disclaimer {
    margin-top: 40px;
}

.disclaimer-box {
    background: linear-gradient(135deg, rgba(239, 83, 80, 0.1), rgba(255, 152, 0, 0.1));
    border: 2px solid var(--accent-orange);
    border-radius: 15px;
    padding: 30px;
    text-align: center;
}

.disclaimer-box h3 {
    font-family: 'Montserrat', sans-serif;
    font-size: 1.4rem;
    font-weight: 700;
    color: var(--accent-orange);
    margin-bottom: 15px;
}

.disclaimer-box p {
    font-size: 1rem;
    font-weight: 500;
    color: var(--text-primary);
    margin-bottom: 10px;
    line-height: 1.8;
}

.disclaimer-box p:last-child {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-top: 20px;
}

/* ========================================
   BACK TO TOP BUTTON
   ======================================== */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    background: var(--accent-cyan);
    color: var(--text-dark);
    border: none;
    padding: 15px 20px;
    font-size: 1rem;
    font-weight: 700;
    border-radius: 50px;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    box-shadow: 0 5px 20px var(--glow-blue);
    z-index: 1000;
}

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

.back-to-top:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 30px var(--glow-blue);
}

/* ========================================
   FOOTER STYLES
   ======================================== */
.main-footer {
    background: var(--secondary-bg);
    padding: 40px 20px;
    text-align: center;
    border-top: 3px solid var(--accent-cyan);
}

.main-footer p {
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 5px;
}

.main-footer p:first-child {
    font-size: 1.2rem;
    color: var(--accent-cyan);
}

/* ========================================
   PRINT STYLES
   ======================================== */
@media print {
    * {
        -webkit-print-color-adjust: exact !important;
        print-color-adjust: exact !important;
        color-adjust: exact !important;
    }

    body {
        background: white !important;
        color: #1a1a2e !important;
        font-size: 11pt;
    }

    .main-header {
        background: #1d3557 !important;
        padding: 30px !important;
        border-bottom: 3px solid #00bcd4 !important;
    }

    .main-header h1 {
        font-size: 24pt !important;
        color: white !important;
    }

    .main-header .subtitle {
        color: #4fc3f7 !important;
    }

    .print-btn,
    .quick-nav,
    .back-to-top {
        display: none !important;
    }

    .content-wrapper {
        max-width: 100% !important;
        padding: 20px !important;
    }

    .stage-section {
        background: #f8f9fa !important;
        border: 2px solid #dee2e6 !important;
        page-break-inside: avoid;
        margin-bottom: 20px !important;
        box-shadow: none !important;
    }

    .stage-header {
        background: #e9ecef !important;
        border-left: 5px solid #00bcd4 !important;
    }

    .stage-header h2 {
        color: #1a1a2e !important;
        font-size: 14pt !important;
    }

    .stage-number {
        color: #1d3557 !important;
    }

    .duration {
        background: #dee2e6 !important;
        color: #1a1a2e !important;
    }

    .stage-content {
        display: block !important;
    }

    .topic-group {
        background: white !important;
        border: 1px solid #dee2e6 !important;
        margin-bottom: 15px !important;
        box-shadow: none !important;
        page-break-inside: avoid;
    }

    .topic-group h3 {
        color: #1d3557 !important;
        border-color: #00bcd4 !important;
        font-size: 12pt !important;
    }

    .topic-group li {
        color: #1a1a2e !important;
        font-size: 10pt !important;
        padding: 8px 0 !important;
        padding-left: 20px !important;
    }

    .topic-group li strong {
        color: #1d3557 !important;
    }

    .topic-group li::before {
        color: #00bcd4 !important;
    }

    .visual-section {
        background: #f8f9fa !important;
        border: 2px solid #dee2e6 !important;
        page-break-before: always;
        box-shadow: none !important;
    }

    .visual-section h2 {
        color: #1d3557 !important;
    }

    .flowchart-container,
    .mindmap-container,
    .roadmap-container {
        page-break-inside: avoid;
    }

    .disclaimer-box {
        background: #fff3cd !important;
        border-color: #ffc107 !important;
    }

    .disclaimer-box h3 {
        color: #856404 !important;
    }

    .disclaimer-box p {
        color: #1a1a2e !important;
    }

    .main-footer {
        background: #1d3557 !important;
        color: white !important;
        padding: 20px !important;
    }

    .main-footer p {
        color: white !important;
    }
}

/* ========================================
   RESPONSIVE STYLES
   ======================================== */
@media (max-width: 1024px) {
    .stage-content {
        grid-template-columns: 1fr;
    }

    .milestone-content {
        max-width: 250px;
    }
}

@media (max-width: 768px) {
    .main-header h1 {
        font-size: 2rem;
    }

    .main-header .subtitle {
        font-size: 1.1rem;
    }

    .nav-buttons {
        flex-direction: column;
        align-items: stretch;
    }

    .nav-btn {
        width: 100%;
    }

    .stage-header {
        flex-direction: column;
        text-align: center;
    }

    .stage-header h2 {
        font-size: 1.4rem;
    }

    .stage-content {
        padding: 20px;
    }

    .visual-section {
        padding: 20px;
    }

    .milestone-content {
        position: relative !important;
        left: auto !important;
        right: auto !important;
        max-width: 100%;
        margin-top: 50px;
        text-align: center !important;
    }

    .milestone-content.left,
    .milestone-content.right {
        left: 10px !important;
        right: 10px !important;
    }

    .timeline-line {
        left: 20px;
    }

    .milestone-marker {
        left: 20px;
    }

    .specialization-boxes {
        flex-direction: column;
        align-items: center;
    }

    .back-to-top {
        bottom: 20px;
        right: 20px;
        padding: 12px 16px;
    }
}

@media (max-width: 480px) {
    .main-header h1 {
        font-size: 1.6rem;
    }

    .stage-number {
        font-size: 1.8rem;
    }

    .topic-group {
        padding: 15px;
    }

    .topic-group li {
        font-size: 0.9rem;
    }
}