/* Navigation */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    transition: var(--transition);
}

.header-scrolled {
    height: 100px !important;
    background: rgba(255, 255, 255, 0.98);
    box-shadow: var(--shadow-md);
}

.header-scrolled .nav-container {
    height: 100px !important;
}

.header-scrolled .logo img:first-child {
    height: 80px !important;
}

.header-scrolled .logo img:last-child {
    height: 80px !important;
}

.header.scrolled {
    padding: 0.5rem 0;
    background: rgba(255, 255, 255, 0.95);
    box-shadow: var(--shadow-md);
}

[data-theme='dark'] .header {
    background: rgba(15, 23, 42, 0.8);
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 100px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-family: var(--font-heading);
    font-weight: 900;
    font-size: 1.25rem;
    color: var(--color-secondary);
}

[data-theme='dark'] .logo {
    color: white;
}

.nav-links {
    display: flex;
    gap: 2rem;
    align-items: center;
}

.nav-link {
    font-weight: 600;
    color: var(--text-main);
}

.nav-link:hover {
    color: var(--color-primary);
}

/* Page Headers (Shared) */
.page-header {
    background: var(--color-hero-grad);
    color: white;
    padding: 10rem 0 5rem;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.page-header h1 {
    font-size: clamp(2.5rem, 5vw, 3.5rem);
    margin-bottom: 1rem;
}

.page-header p {
    font-size: 1.2rem;
    opacity: 0.9;
}

/* Cards */
.card {
    background: var(--bg-card);
    padding: 2rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

.card.featured {
    background: var(--color-secondary);
    color: white;
    border-color: var(--color-secondary);
}

/* Forms */
.form-group {
    margin-bottom: 1.5rem;
}

.form-label {
    display: block;
    font-weight: 700;
    margin-bottom: 0.5rem;
    color: var(--color-secondary);
}

[data-theme='dark'] .form-label {
    color: var(--color-accent);
}

.form-control {
    width: 100%;
    padding: 0.75rem 1rem;
    border-radius: 0.5rem;
    border: 2px solid var(--border-color);
    background: var(--bg-card);
    color: var(--text-main);
    font-family: inherit;
    transition: var(--transition);
}

.form-control:focus {
    outline: none;
    border-color: var(--color-accent);
}

/* Layout Helpers */
.standard-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.sidebar-grid {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 3rem;
}

@media (max-width: 1024px) {
    .sidebar-grid {
        grid-template-columns: 1fr;
    }
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-md);
}

/* Mascot Decoration */
.mascot-placeholder {
    width: 60px;
    height: 60px;
    background: var(--color-accent);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* Dark Mode Toggle */
.theme-toggle {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: var(--color-secondary);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    box-shadow: var(--shadow-md);
    z-index: 1001;
    border: none;
    transition: var(--transition);
}

.theme-toggle:hover {
    transform: scale(1.1);
}

/* Footer */
.footer {
    background: var(--bg-card);
    padding: 4rem 0 2rem;
    border-top: 1px solid var(--border-color);
    margin-top: 5rem;
}

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

.footer-logo {
    filter: grayscale(1);
    opacity: 0.7;
    margin-bottom: 1rem;
}

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

.social-btn {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: var(--border-color);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

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

/* Sections */
.hero {
    background: var(--color-hero-grad);
    color: white;
    padding: 12rem 0 8rem;
    position: relative;
    overflow: hidden;
}

.hero-content {
    max-width: 700px;
    position: relative;
    z-index: 2;
}

.mascot-hero {
    position: absolute;
    right: 15%;
    bottom: 50%;
    transform: translateY(50%);
    width: 450px;
    z-index: 1;
    filter: drop-shadow(0 20px 30px rgba(0, 0, 0, 0.3));
}

@media (max-width: 1024px) {
    .mascot-hero {
        position: static;
        width: 100%;
        max-width: 300px;
        margin: 3rem auto 0;
    }
}

.section-title {
    font-size: 2.5rem;
    margin-bottom: 3rem;
    position: relative;
    padding-bottom: 1rem;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 60px;
    height: 4px;
    background: var(--color-primary);
    border-radius: 2px;
}

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

.section-title.center::after {
    left: 50%;
    transform: translateX(-50%);
}

.day-selector {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-top: 2rem;
    flex-wrap: wrap;
}

.day-tab {
    padding: 1rem 2rem;
    border-radius: var(--radius-lg);
    background: rgba(255, 255, 255, 0.1);
    cursor: pointer;
    transition: var(--transition);
    font-weight: 700;
    border: 2px solid transparent;
}

.day-tab.active {
    background: var(--color-primary);
    color: white;
    border-color: var(--color-primary);
    box-shadow: var(--shadow-vibrant);
}

.timeline-container {
    max-width: 900px;
    margin: 4rem auto;
    position: relative;
    padding: 2rem 0;
}

.timeline-container::before {
    content: '';
    position: absolute;
    left: 50%;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--border-color);
    transform: translateX(-50%);
    border-left: 2px dotted var(--color-accent);
}

.timeline-event {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 4rem;
    width: 100%;
    position: relative;
}

.timeline-event:nth-child(even) {
    flex-direction: row-reverse;
}

.event-time {
    width: 45%;
    text-align: right;
    font-size: 2rem;
    font-weight: 900;
    color: var(--color-primary);
    font-family: var(--font-heading);
}

.timeline-event:nth-child(even) .event-time {
    text-align: left;
}

.event-content {
    width: 45%;
    background: var(--bg-card);
    padding: 2rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    position: relative;
    border: 1px solid var(--border-color);
}

.event-content::after {
    content: '';
    position: absolute;
    top: 20px;
    width: 0;
    height: 0;
    border: 10px solid transparent;
}

.timeline-event:nth-child(odd) .event-content::after {
    right: 100%;
    border-right-color: var(--bg-card);
}

.timeline-event:nth-child(even) .event-content::after {
    left: 100%;
    border-left-color: var(--bg-card);
}

.event-dot {
    position: absolute;
    left: 50%;
    top: 25px;
    width: 20px;
    height: 20px;
    background: white;
    border: 4px solid var(--color-primary);
    border-radius: 50%;
    transform: translateX(-50%);
    z-index: 10;
}

.speaker-frame {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    background: var(--border-color);
    margin-bottom: 1rem;
    overflow: hidden;
    border: 3px solid var(--color-accent);
}

/* Mobile Adjustments */
@media (max-width: 768px) {
    .timeline-container::before {
        left: 30px;
    }

    .timeline-event,
    .timeline-event:nth-child(even) {
        flex-direction: column;
        align-items: flex-start;
        padding-left: 60px;
    }

    .event-time,
    .event-content {
        width: 100%;
        text-align: left;
        margin-bottom: 1rem;
    }

    .event-dot {
        left: 30px;
    }

    .event-content::after {
        display: none;
    }
}

/* Responsive Header & Mobile Menu */
@media (max-width: 768px) {
    .nav-links {
        position: fixed;
        top: 100px;
        left: 0;
        width: 100%;
        background: var(--bg-card);
        flex-direction: column;
        padding: 2rem;
        gap: 1.5rem;
        box-shadow: var(--shadow-md);
        transform: translateY(-150%);
        transition: var(--transition);
        z-index: 999;
    }

    .nav-links.active {
        transform: translateY(0);
    }

    #mobile-menu-btn {
        display: block !important;
        background: none;
        border: none;
        cursor: pointer;
        color: var(--text-main);
    }
}