/* ========================================
   CSS Variables & Reset
   ======================================== */

:root {
    --primary-blue: #2B6FED;
    --dark-blue: #1a4db8;
    --accent-blue: #4A90FF;
    --light-blue: #E8F2FF;
    --navy: #0A1F44;
    --gray-50: #F9FAFB;
    --gray-100: #F3F4F6;
    --gray-300: #D1D5DB;
    --gray-600: #4B5563;
    --gray-900: #111827;
    --white: #FFFFFF;
    --gradient-primary: linear-gradient(135deg, #2B6FED 0%, #4A90FF 100%);
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.04);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 12px 40px rgba(43, 111, 237, 0.15);
    --shadow-xl: 0 20px 60px rgba(43, 111, 237, 0.2);
}

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

body {
    font-family: 'DM Sans', sans-serif;
    color: var(--gray-900);
    line-height: 1.7;
    overflow-x: hidden;
    background: var(--gray-50);
}

/* ========================================
   Navigation
   ======================================== */

nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    z-index: 1000;
    padding: 1.5rem 0;
    box-shadow: var(--shadow-sm);
}

.nav-container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--primary-blue);
    letter-spacing: -0.5px;
}

.btn-nav {
    background: var(--gradient-primary);
    color: white;
    padding: 0.75rem 2rem;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    font-size: 0.95rem;
    transition: all 0.3s ease;
    box-shadow: var(--shadow-md);
}

.btn-nav:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

/* ========================================
   Hero Section
   ======================================== */

.hero {
    padding: 10rem 2rem 6rem;
    background: linear-gradient(135deg, #F0F7FF 0%, #E8F2FF 100%);
    margin-top: 72px;
    text-align: center;
}

.hero-container {
    max-width: 800px;
    margin: 0 auto;
}

.hero h1 {
    font-family: 'Playfair Display', serif;
    font-size: 4rem;
    font-weight: 900;
    line-height: 1.2;
    color: var(--navy);
    margin-bottom: 1.5rem;
    letter-spacing: -2px;
}

.hero h1 .highlight {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero p {
    font-size: 1.3rem;
    color: var(--gray-600);
    margin-bottom: 2rem;
}

/* ========================================
   Modules Main Section (Index Page)
   ======================================== */

.modules-main-section {
    padding: 6rem 2rem;
    background: white;
}

.modules-main-container {
    max-width: 1280px;
    margin: 0 auto;
}

.section-title {
    font-family: 'Playfair Display', serif;
    font-size: 3rem;
    color: var(--navy);
    text-align: center;
    margin-bottom: 1rem;
    font-weight: 900;
}

.section-subtitle {
    font-size: 1.2rem;
    color: var(--gray-600);
    text-align: center;
    margin-bottom: 4rem;
}

.modules-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 2.5rem;
}

.module-box {
    background: white;
    border: 2px solid var(--gray-100);
    border-radius: 24px;
    padding: 2.5rem;
    transition: all 0.4s ease;
    text-align: center;
}

.module-box:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-blue);
}

.module-box-icon {
    font-size: 4rem;
    margin-bottom: 1.5rem;
}

.module-box h3 {
    font-size: 1.8rem;
    color: var(--navy);
    margin-bottom: 1rem;
    font-weight: 700;
}

.module-box p {
    color: var(--gray-600);
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

.module-stats {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin-bottom: 2rem;
    font-size: 0.9rem;
    color: var(--gray-600);
}

.btn-module {
    background: var(--gradient-primary);
    color: white;
    padding: 1rem 2.5rem;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 700;
    display: inline-block;
    transition: all 0.3s ease;
}

.btn-module:hover {
    transform: scale(1.05);
    box-shadow: var(--shadow-lg);
}

/* ========================================
   Module Header Section
   ======================================== */

.module-header-section {
    padding: 8rem 2rem 4rem;
    background: linear-gradient(135deg, #F0F7FF 0%, #E8F2FF 100%);
    margin-top: 72px;
    text-align: center;
}

.module-header-container {
    max-width: 800px;
    margin: 0 auto;
}

.module-header-icon {
    font-size: 5rem;
    margin-bottom: 1.5rem;
}

.module-header-container h1 {
    font-family: 'Playfair Display', serif;
    font-size: 3.5rem;
    color: var(--navy);
    margin-bottom: 1rem;
    font-weight: 900;
}

.module-header-container p {
    font-size: 1.3rem;
    color: var(--gray-600);
    margin-bottom: 2rem;
}

.module-header-stats {
    display: flex;
    justify-content: center;
    gap: 3rem;
    font-size: 1.1rem;
    color: var(--gray-600);
}

/* ========================================
   Topics Section
   ======================================== */

.topics-section {
    padding: 4rem 2rem;
    background: white;
}

.topics-container {
    max-width: 900px;
    margin: 0 auto;
}

.topics-container .section-title {
    margin-bottom: 3rem;
}

.topic-box {
    background: var(--gray-50);
    border: 2px solid var(--gray-100);
    border-radius: 20px;
    padding: 2rem;
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    gap: 2rem;
    transition: all 0.3s ease;
}

.topic-box:hover {
    border-color: var(--primary-blue);
    box-shadow: var(--shadow-md);
    transform: translateX(8px);
}

.topic-number {
    font-size: 2.5rem;
    font-weight: 900;
    color: var(--primary-blue);
    min-width: 80px;
    text-align: center;
}

.topic-content {
    flex: 1;
}

.topic-content h3 {
    font-size: 1.5rem;
    color: var(--navy);
    margin-bottom: 0.5rem;
    font-weight: 700;
}

.topic-content p {
    color: var(--gray-600);
    margin-bottom: 0.75rem;
}

.topic-meta {
    display: flex;
    gap: 2rem;
    font-size: 0.9rem;
    color: var(--gray-600);
}

.btn-topic {
    background: var(--primary-blue);
    color: white;
    padding: 0.75rem 2rem;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    white-space: nowrap;
    transition: all 0.3s ease;
}

.btn-topic:hover {
    background: var(--dark-blue);
    transform: scale(1.05);
}

/* ========================================
   Mavzu Selection Section
   ======================================== */

.mavzu-selection-section {
    padding: 6rem 2rem;
    margin-top: 72px;
    background: var(--gray-50);
    min-height: calc(100vh - 72px);
}

.mavzu-selection-container {
    max-width: 1100px;
    margin: 0 auto;
}

.mavzu-header {
    text-align: center;
    margin-bottom: 4rem;
}

.mavzu-header h1 {
    font-family: 'Playfair Display', serif;
    font-size: 3rem;
    color: var(--navy);
    margin-bottom: 1rem;
    font-weight: 900;
}

.mavzu-header p {
    font-size: 1.2rem;
    color: var(--gray-600);
}

.selection-buttons {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: 3rem;
}

.selection-card {
    background: white;
    border-radius: 24px;
    padding: 3rem;
    box-shadow: var(--shadow-md);
    text-align: center;
    transition: all 0.4s ease;
}

.selection-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
}

.selection-icon {
    font-size: 4rem;
    margin-bottom: 1.5rem;
}

.selection-card h2 {
    font-size: 2rem;
    color: var(--navy);
    margin-bottom: 1rem;
    font-weight: 700;
}

.selection-card p {
    color: var(--gray-600);
    margin-bottom: 2rem;
    line-height: 1.7;
}

.selection-features {
    list-style: none;
    text-align: left;
    margin-bottom: 2rem;
}

.selection-features li {
    padding: 0.75rem 0;
    color: var(--gray-600);
    border-bottom: 1px solid var(--gray-100);
}

.btn-selection {
    background: var(--gradient-primary);
    color: white;
    padding: 1.2rem 3rem;
    border-radius: 50px;
    border: none;
    font-weight: 700;
    font-size: 1.1rem;
    cursor: pointer;
    transition: all 0.3s ease;
    width: 100%;
}

.btn-selection:hover {
    transform: scale(1.05);
    box-shadow: var(--shadow-lg);
}

.btn-selection.btn-secondary {
    background: white;
    color: var(--primary-blue);
    border: 2px solid var(--primary-blue);
}

.btn-selection.btn-secondary:hover {
    background: var(--primary-blue);
    color: white;
}

/* ========================================
   Lecture Section
   ======================================== */

.lecture-section {
    padding: 4rem 2rem;
    margin-top: 72px;
    background: var(--gray-50);
    min-height: calc(100vh - 72px);
}

.lecture-container {
    max-width: 900px;
    margin: 0 auto;
}

#lectureContent {
    background: white;
    border-radius: 24px;
    padding: 3rem;
    box-shadow: var(--shadow-md);
    margin-bottom: 2rem;
}

.lecture-header {
    margin-bottom: 3rem;
    padding-bottom: 2rem;
    border-bottom: 2px solid var(--gray-100);
}

.lecture-breadcrumb {
    color: var(--gray-600);
    font-size: 0.95rem;
    margin-bottom: 1rem;
}

.lecture-title {
    font-family: 'Playfair Display', serif;
    font-size: 3rem;
    color: var(--navy);
    margin-bottom: 1rem;
    font-weight: 900;
}

.lecture-meta {
    display: flex;
    gap: 2rem;
    color: var(--gray-600);
}

.lecture-body {
    font-size: 1.15rem;
    line-height: 1.8;
    color: var(--gray-900);
}

.lecture-body h2 {
    font-size: 2rem;
    color: var(--navy);
    margin: 2.5rem 0 1.5rem;
    font-weight: 700;
}

.lecture-body h3 {
    font-size: 1.5rem;
    color: var(--navy);
    margin: 2rem 0 1rem;
    font-weight: 700;
}

.lecture-body p {
    margin-bottom: 1.5rem;
}

.lecture-body ul, .lecture-body ol {
    margin-bottom: 1.5rem;
    padding-left: 2rem;
}

.lecture-body li {
    margin-bottom: 0.75rem;
}

.lecture-body code {
    background: var(--gray-100);
    padding: 0.2rem 0.6rem;
    border-radius: 6px;
    font-family: 'Courier New', monospace;
    font-size: 0.95em;
    color: var(--primary-blue);
}

.lecture-body pre {
    background: var(--navy);
    color: white;
    padding: 1.5rem;
    border-radius: 12px;
    overflow-x: auto;
    margin: 2rem 0;
}

.lecture-body pre code {
    background: none;
    color: white;
    padding: 0;
}

.info-box {
    background: var(--light-blue);
    border-left: 4px solid var(--primary-blue);
    padding: 1.5rem;
    border-radius: 12px;
    margin: 2rem 0;
}

.code-example {
    background: var(--gray-50);
    border-left: 4px solid var(--primary-blue);
    padding: 1.5rem;
    border-radius: 12px;
    margin: 2rem 0;
}

.lecture-navigation {
    display: flex;
    justify-content: space-between;
    gap: 1rem;
    margin-top: 3rem;
}

.lecture-navigation button,
.lecture-navigation a {
    flex: 1;
}

/* ========================================
   Practice Section
   ======================================== */

.practice-section {
    padding: 4rem 2rem;
    margin-top: 72px;
    background: var(--gray-50);
    min-height: calc(100vh - 72px);
}

.practice-container {
    max-width: 900px;
    margin: 0 auto;
}

#practiceContent {
    background: white;
    border-radius: 24px;
    padding: 3rem;
    box-shadow: var(--shadow-md);
    margin-bottom: 2rem;
}

.practice-header {
    margin-bottom: 3rem;
}

.practice-title {
    font-family: 'Playfair Display', serif;
    font-size: 3rem;
    color: var(--navy);
    margin-bottom: 1rem;
    font-weight: 900;
}

.exercise-box {
    background: var(--gray-50);
    border-radius: 16px;
    padding: 2rem;
    margin-bottom: 2rem;
}

.exercise-box h3 {
    font-size: 1.5rem;
    color: var(--navy);
    margin-bottom: 1rem;
}

.exercise-box p {
    color: var(--gray-600);
    margin-bottom: 1rem;
    line-height: 1.7;
}

.practice-navigation {
    display: flex;
    justify-content: space-between;
    gap: 1rem;
    margin-top: 3rem;
}

.practice-navigation button,
.practice-navigation a {
    flex: 1;
}

/* ========================================
   Common Buttons
   ======================================== */

.btn-primary {
    background: var(--gradient-primary);
    color: white;
    padding: 1rem 2.5rem;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 700;
    font-size: 1rem;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
    display: inline-block;
    text-align: center;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background: white;
    color: var(--primary-blue);
    padding: 1rem 2.5rem;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 700;
    font-size: 1rem;
    transition: all 0.3s ease;
    border: 2px solid var(--primary-blue);
    cursor: pointer;
    display: inline-block;
    text-align: center;
}

.btn-secondary:hover {
    background: var(--primary-blue);
    color: white;
}

/* ========================================
   Footer
   ======================================== */

footer {
    background: var(--navy);
    color: white;
}

.footer-main {
    padding: 4rem 2rem;
}

.footer-content {
    max-width: 1280px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 3rem;
    margin-bottom: 3rem;
}

.footer-section h3 {
    font-size: 1.3rem;
    margin-bottom: 1.5rem;
    color: white;
}

.footer-section p {
    color: rgba(255, 255, 255, 0.7);
    line-height: 1.7;
    margin-bottom: 1.5rem;
}

.social-links {
    display: flex;
    gap: 1rem;
}

.social-links a {
    width: 40px;
    height: 40px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
    color: white;
}

.social-links a:hover {
    background: var(--primary-blue);
    transform: translateY(-3px);
}

.footer-links {
    list-style: none;
}

.footer-links li {
    margin-bottom: 0.8rem;
}

.footer-links a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    transition: all 0.3s ease;
}

.footer-links a:hover {
    color: white;
    padding-left: 5px;
}

.footer-btn {
    display: inline-block;
    background: var(--primary-blue);
    color: white;
    padding: 0.75rem 1.5rem;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    margin-top: 1rem;
}

.footer-btn:hover {
    background: var(--accent-blue);
    transform: translateY(-2px);
}

.footer-app {
    max-width: 1280px;
    margin: 0 auto;
    text-align: center;
    padding-top: 3rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-app h3 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
}

.footer-app p {
    color: rgba(255, 255, 255, 0.7);
    margin-bottom: 2rem;
}

.app-buttons {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    flex-wrap: wrap;
}

.app-btn {
    display: flex;
    align-items: center;
    gap: 1rem;
    background: rgba(255, 255, 255, 0.1);
    padding: 1rem 2rem;
    border-radius: 12px;
    color: white;
    text-decoration: none;
    transition: all 0.3s ease;
}

.app-btn:hover {
    background: rgba(255, 255, 255, 0.15);
    transform: translateY(-3px);
}

.app-btn svg {
    width: 32px;
    height: 32px;
}

.app-btn div {
    text-align: left;
}

.app-btn span {
    display: block;
    font-size: 0.8rem;
    opacity: 0.8;
}

.app-btn strong {
    display: block;
    font-size: 1.1rem;
}

.footer-bottom {
    background: rgba(0, 0, 0, 0.2);
    padding: 1.5rem 2rem;
}

.footer-bottom-content {
    max-width: 1280px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
}

.footer-bottom-links {
    display: flex;
    gap: 2rem;
}

.footer-bottom-links a {
    color: rgba(255, 255, 255, 0.6);
    text-decoration: none;
    font-size: 0.9rem;
    transition: all 0.3s ease;
}

.footer-bottom-links a:hover {
    color: white;
}

/* ========================================
   Feedback Page
   ======================================== */

.feedback-section {
    padding: 6rem 2rem;
    margin-top: 72px;
    background: var(--gray-50);
    min-height: calc(100vh - 72px);
}

.feedback-container {
    max-width: 1200px;
    margin: 0 auto;
}

.feedback-header {
    text-align: center;
    margin-bottom: 4rem;
}

.feedback-header h1 {
    font-family: 'Playfair Display', serif;
    font-size: 3rem;
    color: var(--navy);
    margin-bottom: 1rem;
    font-weight: 900;
}

.feedback-header p {
    font-size: 1.2rem;
    color: var(--gray-600);
}

.feedback-content {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 3rem;
    margin-bottom: 4rem;
}

.feedback-info {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.info-card {
    background: white;
    padding: 2rem;
    border-radius: 16px;
    box-shadow: var(--shadow-sm);
}

.info-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.info-card h3 {
    color: var(--navy);
    margin-bottom: 0.5rem;
    font-size: 1.2rem;
}

.info-card p {
    color: var(--gray-600);
    line-height: 1.6;
}

.feedback-form-container {
    background: white;
    padding: 3rem;
    border-radius: 24px;
    box-shadow: var(--shadow-md);
}

.feedback-form {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.form-group {
    display: flex;
    flex-direction: column;
}

.form-group label {
    font-weight: 600;
    color: var(--navy);
    margin-bottom: 0.5rem;
}

.form-group input,
.form-group select,
.form-group textarea {
    padding: 1rem;
    border: 2px solid var(--gray-100);
    border-radius: 12px;
    font-family: 'DM Sans', sans-serif;
    font-size: 1rem;
    transition: all 0.3s ease;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-blue);
}

.rating-stars {
    display: flex;
    gap: 0.5rem;
    font-size: 2rem;
    cursor: pointer;
}

.star {
    color: var(--gray-300);
    transition: all 0.3s ease;
}

.star:hover,
.star.active {
    color: #FFD700;
}

.btn-submit {
    background: var(--gradient-primary);
    color: white;
    padding: 1.2rem 2rem;
    border-radius: 50px;
    border: none;
    font-weight: 700;
    font-size: 1.1rem;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

.btn-submit:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.contact-info {
    background: white;
    padding: 3rem;
    border-radius: 24px;
    box-shadow: var(--shadow-md);
}

.contact-info h3 {
    font-size: 1.8rem;
    color: var(--navy);
    margin-bottom: 2rem;
    text-align: center;
}

.contact-methods {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.contact-method {
    display: flex;
    align-items: center;
    gap: 1.5rem;
    padding: 1.5rem;
    background: var(--gray-50);
    border-radius: 12px;
    text-decoration: none;
    color: inherit;
    transition: all 0.3s ease;
}

.contact-method:hover {
    background: var(--light-blue);
    transform: translateX(8px);
}

.contact-method svg {
    color: var(--primary-blue);
    flex-shrink: 0;
}

.contact-method div {
    display: flex;
    flex-direction: column;
}

.contact-method strong {
    color: var(--navy);
    margin-bottom: 0.25rem;
}

.contact-method span {
    color: var(--gray-600);
}

/* ========================================
   Author Page
   ======================================== */

.author-section {
    padding: 4rem 2rem;
    margin-top: 72px;
    background: var(--gray-50);
}

.author-container {
    max-width: 1200px;
    margin: 0 auto;
}

.author-hero {
    display: grid;
    grid-template-columns: auto 1fr;
    gap: 3rem;
    align-items: center;
    background: white;
    padding: 3rem;
    border-radius: 24px;
    box-shadow: var(--shadow-md);
    margin-bottom: 3rem;
}

.author-image {
    position: relative;
}

.author-avatar {
    width: 200px;
    height: 200px;
    border-radius: 50%;
    background: var(--gradient-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 6rem;
    box-shadow: var(--shadow-lg);
}

.author-intro h1 {
    font-family: 'Playfair Display', serif;
    font-size: 3rem;
    color: var(--navy);
    margin-bottom: 0.5rem;
    font-weight: 900;
}

.author-title {
    color: var(--primary-blue);
    font-size: 1.3rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
}

.author-bio {
    color: var(--gray-600);
    line-height: 1.8;
    margin-bottom: 2rem;
}

.author-social {
    display: flex;
    gap: 1rem;
}

.social-btn {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    background: var(--gray-50);
    border-radius: 50px;
    text-decoration: none;
    color: var(--navy);
    font-weight: 600;
    transition: all 0.3s ease;
}

.social-btn:hover {
    background: var(--primary-blue);
    color: white;
    transform: translateY(-2px);
}

.author-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.stat-card {
    background: white;
    padding: 2rem;
    border-radius: 16px;
    text-align: center;
    box-shadow: var(--shadow-sm);
}

.stat-number {
    font-size: 3rem;
    font-weight: 900;
    color: var(--primary-blue);
    margin-bottom: 0.5rem;
}

.stat-label {
    color: var(--gray-600);
    font-size: 1.1rem;
}

.author-content {
    display: flex;
    flex-direction: column;
    gap: 3rem;
}

.content-section {
    background: white;
    padding: 3rem;
    border-radius: 24px;
    box-shadow: var(--shadow-md);
}

.content-section h2 {
    font-family: 'Playfair Display', serif;
    font-size: 2.2rem;
    color: var(--navy);
    margin-bottom: 2rem;
    font-weight: 700;
}

.timeline {
    position: relative;
    padding-left: 2rem;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--gray-200);
}

.timeline-item {
    position: relative;
    margin-bottom: 2.5rem;
}

.timeline-dot {
    position: absolute;
    left: -2.5rem;
    top: 0.5rem;
    width: 12px;
    height: 12px;
    background: var(--primary-blue);
    border-radius: 50%;
    border: 3px solid white;
    box-shadow: 0 0 0 2px var(--primary-blue);
}

.timeline-content h3 {
    font-size: 1.4rem;
    color: var(--navy);
    margin-bottom: 0.5rem;
}

.timeline-company {
    color: var(--primary-blue);
    font-weight: 600;
    margin-bottom: 0.25rem;
}

.timeline-date {
    color: var(--gray-600);
    font-size: 0.9rem;
    margin-bottom: 0.75rem;
}

.timeline-content p:last-child {
    color: var(--gray-600);
    line-height: 1.7;
}

.skills-grid {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.skill-item {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.skill-name {
    font-weight: 600;
    color: var(--navy);
}

.skill-bar {
    height: 10px;
    background: var(--gray-100);
    border-radius: 50px;
    overflow: hidden;
}

.skill-progress {
    height: 100%;
    background: var(--gradient-primary);
    border-radius: 50px;
    transition: width 1s ease;
}

.certificates-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.certificate-card {
    background: var(--gray-50);
    padding: 2rem;
    border-radius: 16px;
    text-align: center;
    transition: all 0.3s ease;
}

.certificate-card:hover {
    background: var(--light-blue);
    transform: translateY(-4px);
}

.certificate-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.certificate-card h3 {
    font-size: 1.2rem;
    color: var(--navy);
    margin-bottom: 0.5rem;
}

.certificate-card p {
    color: var(--gray-600);
}

.why-teach p {
    color: var(--gray-600);
    line-height: 1.8;
    margin-bottom: 1.5rem;
}

.author-cta {
    background: var(--gradient-primary);
    color: white;
    padding: 4rem 3rem;
    border-radius: 24px;
    text-align: center;
    box-shadow: var(--shadow-xl);
}

.author-cta h2 {
    font-family: 'Playfair Display', serif;
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.author-cta p {
    font-size: 1.2rem;
    opacity: 0.9;
    margin-bottom: 2rem;
}

.author-cta .btn-primary {
    background: white;
    color: var(--primary-blue);
}

/* ========================================
   Responsive Design
   ======================================== */

@media (max-width: 968px) {
    .hero h1 {
        font-size: 2.5rem;
    }

    .modules-grid {
        grid-template-columns: 1fr;
    }

    .selection-buttons {
        grid-template-columns: 1fr;
    }

    .topic-box {
        flex-direction: column;
        text-align: center;
    }

    .lecture-navigation,
    .practice-navigation {
        flex-direction: column;
    }
}

@media (max-width: 640px) {
    .module-stats,
    .topic-meta,
    .lecture-meta,
    .module-header-stats {
        flex-direction: column;
        gap: 0.5rem;
    }

    .lecture-title,
    .practice-title {
        font-size: 2rem;
    }
}