:root {
    --color-text-main: #1d1d1f;
    --color-text-secondary: #86868b;
    --color-bg-main: #ffffff;
    --color-bg-secondary: #f5f5f7;
    --color-space-grey: #55555a;
    --color-space-grey-dark: #333336;
    --color-border: #d2d2d7;
    --color-white: #ffffff;
    --color-light-grey: #e0e0e0;
    --font-primary: 'Noto Sans TC', sans-serif;
    --font-secondary: 'Montserrat', sans-serif;
    --transition: all 0.4s cubic-bezier(0.25, 1, 0.5, 1);
}

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

body {
    font-family: var(--font-primary);
    line-height: 1.6;
    color: var(--color-text-main);
    background-color: var(--color-bg-main);
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
}

a {
    text-decoration: none;
    color: inherit;
    transition: var(--transition);
}

ul {
    list-style: none;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

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

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-secondary);
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--color-text-main);
}

.section-title {
    font-size: 2.5rem;
    margin-bottom: 3rem;
    position: relative;
    display: inline-block;
    color: var(--color-text-main) !important;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 3px;
    background-color: var(--color-space-grey);
}

.subsection-title {
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
}

/* Sections overrides for light theme */
.section {
    padding: 100px 0;
}

.section-light { background-color: var(--color-bg-main); }
.section-light-grey { background-color: var(--color-bg-secondary); }
.section-dark { background-color: var(--color-bg-main); }
.section-darker { background-color: var(--color-bg-secondary); }

.text-white {
    color: var(--color-text-main) !important; /* Override white text utility */
}

/* Buttons */
.btn-primary {
    display: inline-block;
    background-color: var(--color-text-main);
    color: var(--color-bg-main);
    padding: 10px 24px;
    border-radius: 30px;
    font-weight: 500;
    letter-spacing: 1px;
    border: 1px solid var(--color-text-main);
}

.btn-primary:hover {
    background-color: var(--color-space-grey);
    border-color: var(--color-space-grey);
    color: var(--color-bg-main);
}

.btn-outline {
    display: inline-block;
    background-color: transparent;
    color: var(--color-text-main);
    padding: 12px 30px;
    border-radius: 30px;
    font-weight: 500;
    letter-spacing: 2px;
    border: 1px solid var(--color-text-main);
}

.btn-outline:hover {
    background-color: var(--color-text-main);
    color: var(--color-bg-main);
}

/* Navbar */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background-color: transparent;
    padding: 15px 0;
    z-index: 1000;
    transition: background-color 0.4s cubic-bezier(0.25, 1, 0.5, 1), border-bottom 0.4s cubic-bezier(0.25, 1, 0.5, 1), backdrop-filter 0.4s cubic-bezier(0.25, 1, 0.5, 1);
    border-bottom: 1px solid transparent;
}

.navbar::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0; bottom: 0;
    background: linear-gradient(rgba(0,0,0,0.6) 0%, rgba(0,0,0,0) 100%);
    z-index: -1;
    transition: opacity 0.5s cubic-bezier(0.25, 1, 0.5, 1);
    pointer-events: none;
}

.navbar.scrolled::before {
    opacity: 0;
}

.navbar.scrolled {
    background-color: rgba(255, 255, 255, 0.8);
    backdrop-filter: saturate(180%) blur(20px);
    -webkit-backdrop-filter: saturate(180%) blur(20px);
    border-bottom: 1px solid var(--color-border);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: relative;
    z-index: 1;
}

.nav-logo-img {
    height: 40px;
    width: auto;
    object-fit: contain;
    display: block;
    transition: var(--transition);
}

.nav-links {
    display: flex;
    gap: 30px;
}

.nav-links a {
    color: var(--color-white);
    font-weight: 500;
    font-size: 0.95rem;
    text-shadow: 0 1px 4px rgba(0,0,0,0.5);
}

.nav-links a:hover {
    color: var(--color-light-grey);
}

.navbar.scrolled .nav-links a {
    color: var(--color-text-secondary);
    text-shadow: none;
}

.navbar.scrolled .nav-links a:hover {
    color: var(--color-text-main);
}

.navbar .btn-primary {
    background-color: transparent;
    color: #ffffff;
    border-color: #ffffff;
}

.navbar.scrolled .btn-primary {
    background-color: var(--color-text-main);
    color: var(--color-bg-main);
    border-color: var(--color-text-main);
}

.navbar.scrolled .btn-primary:hover {
    background-color: var(--color-space-grey);
    border-color: var(--color-space-grey);
    color: var(--color-bg-main);
}

/* Hero Section */
.hero {
    height: 100vh;
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    color: var(--color-white);
    background-size: cover;
    background-position: center;
    background-attachment: fixed;
    padding-top: 80px;
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(rgba(0, 0, 0, 0.6) 0%, rgba(0, 0, 0, 0.3) 100%);
    background-color: rgba(0, 0, 0, 0.4) !important;
    z-index: 1;
}

.hero-content {
    position: relative;
    z-index: 2;
    max-width: 800px;
    padding: 0 20px;
    text-shadow: 0 2px 10px rgba(0, 0, 0, 0.5);
}

.hero h1 {
    font-size: clamp(1.2rem, 3.5vw, 3rem) !important;
    white-space: nowrap !important;
    color: #FFFFFF !important;
    margin-bottom: 30px;
    line-height: 1.2;
    letter-spacing: 2px;
}

.hero h2 {
    font-size: 1.2rem;
    font-weight: 500;
    color: #FFFFFF !important;
    margin-bottom: 15px;
    letter-spacing: 3px;
    text-transform: uppercase;
}

.hero .btn-outline {
    display: inline-block;
    background-color: transparent;
    color: #FFFFFF !important;
    padding: 12px 30px;
    border-radius: 30px;
    font-weight: 500;
    letter-spacing: 2px;
    border: 1px solid #FFFFFF !important;
}

.hero .btn-outline:hover {
    background-color: var(--color-white);
    color: var(--color-text-main);
}

/* Course Grid */
.course-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 30px;
}

.course-card {
    background-color: var(--color-bg-main);
    border-radius: 18px;
    overflow: hidden;
    transition: transform 0.5s cubic-bezier(0.25, 1, 0.5, 1), box-shadow 0.5s cubic-bezier(0.25, 1, 0.5, 1);
    cursor: pointer;
    box-shadow: 0 4px 20px rgba(0,0,0,0.04);
    border: 1px solid var(--color-border);
}

.course-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 15px 35px rgba(0,0,0,0.1);
}

.course-img-wrap {
    height: 200px;
    overflow: hidden;
}

.course-img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.6s cubic-bezier(0.25, 1, 0.5, 1);
}

.course-card:hover .course-img {
    transform: scale(1.05);
}

.course-content {
    padding: 25px;
}

.course-content h3 {
    font-size: 1.25rem;
    margin-bottom: 15px;
    color: var(--color-text-main);
    line-height: 1.4;
}

.course-content p {
    color: var(--color-text-secondary);
    font-size: 0.95rem;
    margin-bottom: 20px;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.course-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-top: 1px solid var(--color-border);
    padding-top: 15px;
    font-size: 0.85rem;
    color: var(--color-space-grey);
    font-weight: 500;
}

.course-card.coming-soon-card {
    background: #ffffff;
    border: 1px solid rgba(0, 0, 0, 0.08);
    min-height: 320px;
    padding: 28px 24px;
    display: flex;
    justify-content: center;
    align-items: center;
    box-shadow: none;
}

.course-card.coming-soon-card:hover {
    transform: none;
    box-shadow: none;
}

.course-card.coming-soon-card .coming-soon-text {
    text-align: center;
    color: #2c2c2c;
    line-height: 1.7;
}

.course-card.coming-soon-card .coming-soon-text p {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 0.85rem;
}

.course-card.coming-soon-card .coming-soon-text span {
    display: inline-block;
    font-size: 0.95rem;
    opacity: 0.7;
}

.course-preview-card {
    background: #ffffff;
    border: 1px solid rgba(0, 0, 0, 0.08);
    min-height: 240px;
    padding: 24px 26px;
    box-shadow: none;
    cursor: default;
}

.course-preview-card:hover {
    transform: none;
}

.course-preview-card .preview-label {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 8px 14px;
    border-radius: 999px;
    background-color: rgba(0, 0, 0, 0.05);
    color: #2c2c2c;
    font-size: 0.82rem;
    font-weight: 700;
    letter-spacing: 0.08em;
    margin-bottom: 1rem;
}

.course-preview-card .preview-item {
    margin-bottom: 18px;
    padding-bottom: 16px;
    border-bottom: 1px solid rgba(0, 0, 0, 0.06);
}

.course-preview-card .preview-item:last-child {
    margin-bottom: 0;
    padding-bottom: 0;
    border-bottom: none;
}

.course-preview-card .preview-item-title {
    font-size: 1.05rem;
    font-weight: 700;
    color: #1f1f1f;
    margin-bottom: 0.35rem;
}

.course-preview-card .preview-item-meta {
    margin: 0;
    color: #454545;
    font-size: 0.95rem;
    line-height: 1.7;
}


/* Co-organizers Display */
.co-organizers-display {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    align-items: center;
    gap: 40px;
}

.co-org-item {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--color-space-grey-dark);
    padding: 15px 30px;
    background: var(--color-bg-main);
    border-radius: 12px;
    border: 1px solid var(--color-border);
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 15px rgba(0,0,0,0.03);
    transition: var(--transition);
}

.co-org-item:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 25px rgba(0,0,0,0.08);
    color: var(--color-text-main);
    border-color: var(--color-space-grey);
}

.co-org-item.has-logo {
    padding: 10px 20px;
}

.co-org-logo {
    max-height: 50px;
    width: auto;
    object-fit: contain;
}

/* Teacher Grid */
.teacher-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 40px;
}

.teacher-card {
    background: var(--color-bg-main);
    padding: 40px 20px;
    border-radius: 18px;
    text-align: center;
    box-shadow: 0 4px 20px rgba(0,0,0,0.04);
    transition: var(--transition);
    border: 1px solid var(--color-border);
    cursor: pointer;
}

.teacher-card:hover {
    box-shadow: 0 15px 35px rgba(0,0,0,0.1);
    transform: translateY(-5px);
}

.teacher-img {
    width: 120px;
    height: 120px;
    border-radius: 50%;
    object-fit: cover;
    margin: 0 auto 20px;
    border: 3px solid var(--color-bg-secondary);
    transition: var(--transition);
}

.teacher-card:hover .teacher-img {
    border-color: var(--color-space-grey);
}

.teacher-name {
    font-size: 1.4rem;
    margin-bottom: 5px;
}

.teacher-title {
    font-size: 0.9rem;
    color: var(--color-text-secondary);
    margin-bottom: 15px;
}

.teacher-exp {
    font-size: 0.85rem;
    text-align: left;
    margin-top: 20px;
    padding-top: 20px;
    border-top: 1px solid var(--color-border);
}
.teacher-exp ul {
    list-style-type: none;
    padding-left: 0;
}
.teacher-exp li {
    position: relative;
    padding-left: 15px;
    margin-bottom: 6px;
    color: var(--color-text-secondary);
}
.teacher-exp li::before {
    content: '•';
    position: absolute;
    left: 0;
    color: var(--color-space-grey);
}

/* Registration */
.registration-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin-top: 50px;
}

.reg-step {
    background: var(--color-bg-main);
    border: 1px solid var(--color-border);
    padding: 40px 30px;
    border-radius: 18px;
    position: relative;
    overflow: hidden;
    box-shadow: 0 4px 20px rgba(0,0,0,0.04);
}

.reg-step::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: var(--color-space-grey);
}

.reg-step h3 {
    color: var(--color-text-main);
    margin-bottom: 20px;
    font-size: 1.3rem;
}

.reg-step ul {
    color: var(--color-text-secondary);
    font-size: 0.95rem;
}

.reg-step li {
    margin-bottom: 10px;
    position: relative;
    padding-left: 20px;
}

.reg-step li::before {
    content: '→';
    position: absolute;
    left: 0;
    color: var(--color-space-grey);
}

.reg-step a {
    color: var(--color-space-grey-dark);
    text-decoration: underline;
    font-weight: 500;
}

/* Contact & Footer */
.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 50px;
    align-items: stretch;
}

.map-container {
    width: 100%;
    height: 450px;
    position: relative;
    min-height: 350px;
    border-radius: 12px;
    overflow: hidden;
    background-color: var(--color-bg-secondary);
}

.map-container iframe {
    width: 100%;
    height: 100%;
    border: 0;
}

#map-loader {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    z-index: 5;
    background-color: var(--color-bg-secondary);
}

.spinner {
    width: 40px;
    height: 40px;
    border: 4px solid var(--color-border);
    border-top: 4px solid var(--color-space-grey-dark);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.footer {
    background-color: var(--color-space-grey-dark);
    color: var(--color-light-grey);
    padding: 60px 0 20px;
    border-top: none;
}

.footer-grid {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    gap: 40px;
    margin-bottom: 40px;
}

.footer h4 {
    color: var(--color-white);
    margin-bottom: 20px;
}

.footer-col ul li, .footer-col p {
    margin-bottom: 10px;
    font-size: 0.9rem;
    color: var(--color-light-grey);
}

.footer-col ul li a, .footer-col p a {
    color: var(--color-light-grey);
}

.footer-col ul li a:hover, .footer-col p a:hover {
    color: var(--color-white);
}

.footer-bottom {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    font-size: 0.85rem;
    color: var(--color-light-grey);
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    z-index: 2000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow: auto;
    background-color: rgba(29, 29, 31, 0.5);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
}

.modal-content {
    background-color: var(--color-bg-main);
    margin: 5% auto;
    padding: 40px;
    width: 90%;
    max-width: 1200px;
    border-radius: 24px;
    position: relative;
    box-shadow: 0 25px 50px rgba(0,0,0,0.15);
    animation: modalFadeIn 0.5s cubic-bezier(0.16, 1, 0.3, 1);
}

@keyframes modalFadeIn {
    from { opacity: 0; transform: translateY(30px) scale(0.98); }
    to { opacity: 1; transform: translateY(0) scale(1); }
}

.close-btn {
    color: var(--color-text-secondary);
    position: absolute;
    top: 20px;
    right: 30px;
    font-size: 2rem;
    font-weight: 300;
    cursor: pointer;
}

.close-btn:hover {
    color: var(--color-text-main);
}

.modal-body-content h2 {
    font-size: 2rem;
    margin-bottom: 10px;
}

.modal-tag {
    display: inline-block;
    background: var(--color-bg-secondary);
    color: var(--color-space-grey-dark);
    padding: 5px 14px;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 500;
    margin-bottom: 20px;
    border: 1px solid var(--color-border);
}

.modal-section {
    margin-bottom: 25px;
}

.modal-section h4 {
    font-size: 1.1rem;
    margin-bottom: 10px;
    border-bottom: 1px solid var(--color-border);
    padding-bottom: 5px;
    color: var(--color-text-main);
}

.modal-section p {
    color: var(--color-text-secondary);
}

.modal-section ul {
    padding-left: 20px;
    list-style-type: disc;
    color: var(--color-text-secondary);
}

.modal-section li {
    margin-bottom: 5px;
}

.schedule-pre {
    background: var(--color-bg-secondary);
    padding: 20px;
    border-radius: 12px;
    font-family: var(--font-primary);
    white-space: pre-wrap;
    font-size: 0.9rem;
    color: var(--color-text-main);
    border: 1px solid var(--color-border);
}

/* Animations */
.fade-in-up {
    animation: fadeInUp 1.2s cubic-bezier(0.16, 1, 0.3, 1) both;
}

.delay-1 { animation-delay: 0.2s; }
.delay-2 { animation-delay: 0.4s; }

@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Dropdown Menu Styles */
.nav-links .dropdown {
    position: relative;
    display: flex;
    align-items: center;
}

.nav-links .dropdown-content {
    display: none;
    position: absolute;
    top: 100%;
    left: 50%;
    transform: translateX(-50%);
    background-color: var(--color-bg-main);
    min-width: 120px;
    box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.1);
    z-index: 1000;
    border-radius: 4px;
    padding: 8px 0;
    flex-direction: column;
}

.nav-links .dropdown:hover .dropdown-content {
    display: flex;
}

.nav-links .dropdown-content a {
    color: var(--color-text-main) !important;
    text-shadow: none !important;
    padding: 10px 20px;
    text-align: center;
    width: 100%;
    box-sizing: border-box;
    font-size: 0.9rem;
}

.nav-links .dropdown-content a:hover {
    background-color: var(--color-bg-secondary);
    color: var(--color-text-main) !important;
}

/* Responsive */
@media (max-width: 768px) {
    .nav-links { display: none; }
    .hero h1 { font-size: 1.8rem; white-space: nowrap; }
    .hero h2 { font-size: 1rem; }
    .contact-grid, .footer-grid { grid-template-columns: 1fr; }
    .section-title { font-size: 2rem; }
}