/* CSS Variables */
:root {
    /* Colors - Black & White Palette */
    --color-black: #0a0a0a;
    --color-dark-gray: #1a1a1a;
    --color-medium-gray: #808080;
    --color-light-gray: #e5e5e5;
    --color-white: #ffffff;
    --color-off-white: #f8f8f8;

    /* Typography */
    --font-heading: 'Montserrat', sans-serif;
    --font-body: 'Inter', sans-serif;

    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 4rem;
    --spacing-xl: 6rem;

    /* Transitions */
    --transition-fast: 300ms ease;
    --transition-slow: 600ms ease;

    /* Shadows */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.15);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.2);

    /* Container */
    --container-width: 1440px;
    --container-padding: 2rem;
}

/* Typography */
body {
    font-family: var(--font-body);
    font-size: 16px;
    line-height: 1.8;
    color: var(--color-dark-gray);
    background-color: var(--color-white);
}

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    font-weight: 700;
    line-height: 1.2;
    color: var(--color-black);
    margin-bottom: var(--spacing-sm);
}

h1 {
    font-size: clamp(2.5rem, 5vw, 4.5rem);
    font-weight: 800;
    letter-spacing: -0.02em;
}

h2 {
    font-size: clamp(2rem, 4vw, 3.5rem);
    font-weight: 700;
}

h3 {
    font-size: clamp(1.5rem, 3vw, 2.5rem);
    font-weight: 600;
}

h4 {
    font-size: clamp(1.25rem, 2vw, 1.75rem);
    font-weight: 600;
}

h5 {
    font-size: 1.25rem;
    font-weight: 500;
}

h6 {
    font-size: 1rem;
    font-weight: 500;
}

p {
    margin-bottom: var(--spacing-sm);
    font-size: 1rem;
    line-height: 1.8;
}

/* Container */
.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 var(--container-padding);
}

/* Sections */
section {
    padding: var(--spacing-xl) 0;
}

.section-dark {
    background-color: var(--color-black);
    color: var(--color-white);
}

.section-dark h1,
.section-dark h2,
.section-dark h3,
.section-dark h4,
.section-dark h5,
.section-dark h6 {
    color: var(--color-white);
}

.section-light {
    background-color: var(--color-white);
}

.section-schedule {
    padding: 0.5rem 0 1rem;
}

.section-gray {
    background-color: var(--color-off-white);
}

/* Grid Layouts */
.grid {
    display: grid;
    gap: var(--spacing-md);
}

.grid-2 {
    grid-template-columns: repeat(2, 1fr);
}

.grid-3 {
    grid-template-columns: repeat(3, 1fr);
}

.grid-4 {
    grid-template-columns: repeat(4, 1fr);
}

/* Utility Classes */
.text-center {
    text-align: center;
}

.text-white {
    color: var(--color-white);
}

.mb-0 { margin-bottom: 0; }
.mb-xs { margin-bottom: var(--spacing-xs); }
.mb-sm { margin-bottom: var(--spacing-sm); }
.mb-md { margin-bottom: var(--spacing-md); }
.mb-lg { margin-bottom: var(--spacing-lg); }
.mb-xl { margin-bottom: var(--spacing-xl); }

.mt-0 { margin-top: 0; }
.mt-xs { margin-top: var(--spacing-xs); }
.mt-sm { margin-top: var(--spacing-sm); }
.mt-md { margin-top: var(--spacing-md); }
.mt-lg { margin-top: var(--spacing-lg); }
.mt-xl { margin-top: var(--spacing-xl); }

/* Navigation */
.header {
    position: sticky;
    top: 0;
    background-color: var(--color-white);
    border-bottom: 1px solid var(--color-light-gray);
    z-index: 1000;
    transition: all var(--transition-fast);
}

.header.scrolled {
    box-shadow: var(--shadow-sm);
}

.nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.75rem 0;
    min-height: 60px;
}

.logo {
    font-family: var(--font-heading);
    font-size: 1.75rem;
    font-weight: 800;
    letter-spacing: 0.1em;
    color: var(--color-black);
    transition: opacity var(--transition-fast);
}

.logo:hover {
    opacity: 0.7;
}

.nav-menu {
    display: flex;
    gap: var(--spacing-md);
    align-items: center;
}

.nav-link {
    font-family: var(--font-heading);
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--color-dark-gray);
    position: relative;
    transition: color var(--transition-fast);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--color-black);
    transition: width var(--transition-fast);
}

.nav-link:hover,
.nav-link.active {
    color: var(--color-black);
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

.burger {
    display: none;
    flex-direction: column;
    justify-content: space-between;
    gap: 0;
    width: 28px;
    height: 21px;
    cursor: pointer;
    margin-right: 0.25rem;
    position: relative;
}

.burger-line {
    width: 100%;
    height: 3px;
    background-color: var(--color-black);
    transition: all var(--transition-fast);
    transform-origin: center;
}

.burger-line:nth-child(2) {
    transition: opacity 150ms ease;
}

.burger.active .burger-line:nth-child(1) {
    transform: translateY(9px) rotate(45deg);
}

.burger.active .burger-line:nth-child(2) {
    opacity: 0;
}

.burger.active .burger-line:nth-child(3) {
    transform: translateY(-9px) rotate(-45deg);
}

/* Footer */
.footer {
    background-color: var(--color-black);
    color: var(--color-white);
    padding: var(--spacing-lg) 0 var(--spacing-md);
    position: relative;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
}

.footer-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
    color: var(--color-white);
}

.footer-text {
    font-size: 0.95rem;
    color: var(--color-light-gray);
    line-height: 1.8;
}

.footer-link {
    color: var(--color-light-gray);
    transition: color var(--transition-fast);
}

.footer-link:hover {
    color: var(--color-white);
}

.social-links {
    display: flex;
    gap: var(--spacing-sm);
}

.social-link {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background-color: var(--color-dark-gray);
    border-radius: 4px;
    transition: background-color var(--transition-fast);
}

.social-link:hover {
    background-color: var(--color-medium-gray);
}

.social-link svg {
    width: 18px;
    height: 18px;
}

.footer-bottom {
    text-align: center;
    padding-top: var(--spacing-md);
    border-top: 1px solid var(--color-dark-gray);
}

.copyright {
    font-size: 0.85rem;
    color: var(--color-medium-gray);
}

/* Scroll to Top Button */
.scroll-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 48px;
    height: 48px;
    background-color: var(--color-black);
    color: var(--color-white);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-fast);
    z-index: 999;
}

.scroll-top.visible {
    opacity: 1;
    visibility: visible;
}

.scroll-top:hover {
    background-color: var(--color-dark-gray);
    transform: translateY(-4px);
}

.scroll-top svg {
    width: 24px;
    height: 24px;
}