/* ===========================
   CSS Custom Properties
   =========================== */
:root {
    --bg-primary: #fafafa;
    --bg-secondary: #ffffff;
    --bg-alt: #f0f0f0;
    --text-primary: #1a1a2e;
    --text-secondary: #444;
    --text-muted: #777;
    --accent: #D97757;
    --accent-hover: #c4613f;
    --card-bg: #ffffff;
    --card-border: #e0e0e0;
    --card-shadow: rgba(0, 0, 0, 0.06);
    --nav-bg: rgba(250, 250, 250, 0.92);
    --nav-border: rgba(0, 0, 0, 0.08);
    --footer-bg: #1a1a2e;
    --footer-text: #ccc;
    --code-bg: #f5f5f5;
    --transition-speed: 0.3s;
}

[data-theme="dark"] {
    --bg-primary: #1a1a2e;
    --bg-secondary: #16213e;
    --bg-alt: #0f3460;
    --text-primary: #f0f0f0;
    --text-secondary: #c0c0c0;
    --text-muted: #999;
    --accent: #D97757;
    --accent-hover: #e8906e;
    --card-bg: #16213e;
    --card-border: #2a2a4a;
    --card-shadow: rgba(0, 0, 0, 0.2);
    --nav-bg: rgba(26, 26, 46, 0.92);
    --nav-border: rgba(255, 255, 255, 0.08);
    --footer-bg: #0f0f1e;
    --footer-text: #aaa;
    --code-bg: #2a2a4a;
}

/* ===========================
   Base Reset & Typography
   =========================== */
*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    scroll-padding-top: 70px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen,
        Ubuntu, Cantarell, "Fira Sans", "Droid Sans", "Helvetica Neue", sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    transition: background-color var(--transition-speed) ease,
                color var(--transition-speed) ease;
}

a {
    color: var(--accent);
    text-decoration: none;
    transition: color var(--transition-speed) ease;
}

a:hover {
    color: var(--accent-hover);
}

img {
    max-width: 100%;
    display: block;
}

.container {
    width: 100%;
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 20px;
}

/* ===========================
   Navigation
   =========================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background-color: var(--nav-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--nav-border);
    transition: background-color var(--transition-speed) ease,
                border-color var(--transition-speed) ease;
}

.nav-container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: -0.02em;
}

.nav-logo:hover {
    color: var(--accent);
}

.nav-logo-img {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    object-fit: cover;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 28px;
}

.nav-links a {
    color: var(--text-secondary);
    font-size: 0.92rem;
    font-weight: 500;
    transition: color var(--transition-speed) ease;
}

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

/* Theme Toggle */
.theme-toggle {
    background: none;
    border: 2px solid var(--card-border);
    border-radius: 50%;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    color: var(--text-primary);
    transition: border-color var(--transition-speed) ease,
                color var(--transition-speed) ease,
                transform 0.2s ease;
}

.theme-toggle:hover {
    border-color: var(--accent);
    color: var(--accent);
    transform: scale(1.05);
}

.icon-moon {
    display: none;
}

[data-theme="dark"] .icon-sun {
    display: none;
}

[data-theme="dark"] .icon-moon {
    display: block;
}

/* Hamburger */
.hamburger {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
    z-index: 1001;
}

.hamburger .bar {
    display: block;
    width: 24px;
    height: 2px;
    background-color: var(--text-primary);
    border-radius: 2px;
    transition: transform 0.3s ease, opacity 0.3s ease;
}

.hamburger.active .bar:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
}

.hamburger.active .bar:nth-child(2) {
    opacity: 0;
}

.hamburger.active .bar:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
}

/* ===========================
   Hero Section
   =========================== */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    overflow: hidden;
    padding: 100px 20px 60px;
}

.hero-bg {
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, var(--bg-primary) 0%, var(--bg-secondary) 40%, var(--accent) 150%);
    background-size: 200% 200%;
    animation: gradientShift 12s ease infinite;
    z-index: 0;
    transition: background var(--transition-speed) ease;
}

[data-theme="dark"] .hero-bg {
    background: linear-gradient(135deg, #1a1a2e 0%, #16213e 40%, #D97757 180%);
    background-size: 200% 200%;
    animation: gradientShift 12s ease infinite;
}

@keyframes gradientShift {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

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

.hero h1 {
    font-size: clamp(2.2rem, 5vw, 3.8rem);
    font-weight: 800;
    line-height: 1.15;
    margin-bottom: 20px;
    letter-spacing: -0.03em;
}

.accent {
    color: var(--accent);
}

.hero-tagline {
    font-size: clamp(1rem, 2vw, 1.25rem);
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto 36px;
    line-height: 1.7;
}

/* ===========================
   Buttons
   =========================== */
.btn {
    display: inline-block;
    padding: 14px 32px;
    font-size: 1rem;
    font-weight: 600;
    border-radius: 8px;
    cursor: pointer;
    text-align: center;
    transition: transform 0.2s ease, box-shadow 0.2s ease,
                background-color var(--transition-speed) ease,
                color var(--transition-speed) ease;
}

.btn:hover {
    transform: translateY(-2px);
}

.btn-primary {
    background-color: var(--accent);
    color: #fff;
    border: none;
}

.btn-primary:hover {
    background-color: var(--accent-hover);
    color: #fff;
    box-shadow: 0 6px 20px rgba(217, 119, 87, 0.35);
}

.btn-secondary {
    background-color: transparent;
    color: var(--accent);
    border: 2px solid var(--accent);
}

.btn-secondary:hover {
    background-color: var(--accent);
    color: #fff;
    box-shadow: 0 6px 20px rgba(217, 119, 87, 0.25);
}

/* ===========================
   Sections
   =========================== */
.section {
    padding: 100px 0;
    transition: background-color var(--transition-speed) ease;
}

.section-alt {
    background-color: var(--bg-secondary);
}

.section-title {
    font-size: clamp(1.8rem, 3.5vw, 2.6rem);
    font-weight: 800;
    text-align: center;
    margin-bottom: 16px;
    letter-spacing: -0.02em;
}

.section-subtitle {
    text-align: center;
    color: var(--text-secondary);
    font-size: 1.1rem;
    margin-bottom: 48px;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

/* ===========================
   About Section
   =========================== */
.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 48px;
    margin-top: 48px;
    align-items: start;
}

.about-text p {
    color: var(--text-secondary);
    margin-bottom: 16px;
    font-size: 1.05rem;
    line-height: 1.8;
}

.about-text strong {
    color: var(--text-primary);
}

.about-highlights {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.highlight-item {
    display: flex;
    gap: 16px;
    align-items: flex-start;
    padding: 20px;
    background-color: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 12px;
    transition: transform 0.2s ease, box-shadow 0.2s ease,
                background-color var(--transition-speed) ease,
                border-color var(--transition-speed) ease;
}

.highlight-item:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 16px var(--card-shadow);
}

.highlight-icon {
    font-size: 1.6rem;
    flex-shrink: 0;
    width: 40px;
    text-align: center;
}

.highlight-item h3 {
    font-size: 1.05rem;
    font-weight: 700;
    margin-bottom: 4px;
}

.highlight-item p {
    font-size: 0.92rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* ===========================
   Claude Section
   =========================== */
.claude-content {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}

.claude-content > p {
    font-size: 1.1rem;
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: 40px;
}

.claude-features {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 24px;
    margin-bottom: 36px;
    text-align: left;
}

.feature-item {
    padding: 24px;
    background-color: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 12px;
    transition: transform 0.2s ease, box-shadow 0.2s ease,
                background-color var(--transition-speed) ease,
                border-color var(--transition-speed) ease;
}

.feature-item:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 16px var(--card-shadow);
}

.feature-item h3 {
    font-size: 1rem;
    font-weight: 700;
    margin-bottom: 8px;
}

.feature-item p {
    font-size: 0.92rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* ===========================
   Benefits Cards
   =========================== */
.benefits-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
    margin-top: 48px;
}

.card {
    background-color: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 12px;
    padding: 32px 24px;
    text-align: center;
    transition: transform 0.2s ease, box-shadow 0.2s ease,
                background-color var(--transition-speed) ease,
                border-color var(--transition-speed) ease;
}

.card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 24px var(--card-shadow);
}

.card-icon {
    font-size: 2.2rem;
    margin-bottom: 16px;
}

.card h3 {
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 12px;
}

.card p {
    font-size: 0.92rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* ===========================
   Events Section
   =========================== */
.events-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 24px;
}

.event-card {
    background-color: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 12px;
    padding: 28px;
    position: relative;
    transition: transform 0.2s ease, box-shadow 0.2s ease,
                background-color var(--transition-speed) ease,
                border-color var(--transition-speed) ease;
}

.event-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 20px var(--card-shadow);
}

.event-tag {
    display: inline-block;
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    padding: 4px 12px;
    border-radius: 20px;
    margin-bottom: 14px;
}

.event-tag.upcoming {
    background-color: rgba(217, 119, 87, 0.15);
    color: var(--accent);
}

.event-tag.project {
    background-color: rgba(72, 149, 239, 0.15);
    color: #4895ef;
}

.event-card h3 {
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 8px;
}

.event-card p {
    font-size: 0.92rem;
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 12px;
}

.event-date {
    font-size: 0.82rem;
    color: var(--text-muted);
    font-weight: 500;
}

/* ===========================
   Resources Section
   =========================== */
.resources-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

.resource-link {
    display: block;
    padding: 24px;
    background-color: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 12px;
    color: var(--text-primary);
    position: relative;
    transition: transform 0.2s ease, box-shadow 0.2s ease,
                background-color var(--transition-speed) ease,
                border-color var(--transition-speed) ease;
}

.resource-link:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 20px var(--card-shadow);
    color: var(--text-primary);
    border-color: var(--accent);
}

.resource-link h3 {
    font-size: 1rem;
    font-weight: 700;
    margin-bottom: 8px;
}

.resource-link p {
    font-size: 0.88rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

.link-arrow {
    position: absolute;
    top: 24px;
    right: 24px;
    color: var(--accent);
    font-size: 1.2rem;
    transition: transform 0.2s ease;
}

.resource-link:hover .link-arrow {
    transform: translateX(4px);
}

/* ===========================
   Join Section
   =========================== */
.join-container {
    text-align: center;
    max-width: 640px;
}

.join-text {
    font-size: 1.15rem;
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: 36px;
}

.join-buttons {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
}

/* ===========================
   Footer
   =========================== */
.footer {
    background-color: var(--footer-bg);
    color: var(--footer-text);
    padding: 48px 0 32px;
    transition: background-color var(--transition-speed) ease;
}

.footer-top {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 40px;
}

.footer-brand {
    display: flex;
    align-items: center;
    gap: 14px;
}

.footer-logo-img {
    width: 44px;
    height: 44px;
    border-radius: 50%;
    object-fit: cover;
}

.footer-brand h3 {
    color: #fff;
    font-size: 1.2rem;
    margin: 0;
}

.footer-brand p {
    color: var(--footer-text);
    font-size: 0.88rem;
    margin: 0;
}

.footer-socials {
    display: flex;
    gap: 16px;
}

.social-link {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 42px;
    height: 42px;
    border-radius: 50%;
    border: 1px solid rgba(255, 255, 255, 0.15);
    color: var(--footer-text);
    transition: color var(--transition-speed) ease,
                border-color var(--transition-speed) ease,
                transform 0.2s ease;
}

.social-link:hover {
    color: var(--accent);
    border-color: var(--accent);
    transform: translateY(-2px);
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: 24px;
    text-align: center;
    font-size: 0.88rem;
}

.footer-bottom a {
    color: var(--accent);
    font-weight: 600;
}

/* ===========================
   Fade-in Animations
   =========================== */
.fade-in {
    opacity: 0;
    transform: translateY(24px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ===========================
   Responsive Design
   =========================== */
@media (max-width: 900px) {
    .benefits-grid {
        grid-template-columns: 1fr 1fr;
    }

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

}

@media (max-width: 768px) {
    .hamburger {
        display: flex;
    }

    .nav-links {
        position: fixed;
        top: 0;
        right: -100%;
        width: 280px;
        height: 100vh;
        background-color: var(--bg-primary);
        flex-direction: column;
        align-items: center;
        justify-content: center;
        gap: 24px;
        transition: right 0.35s ease, background-color var(--transition-speed) ease;
        box-shadow: -4px 0 20px rgba(0, 0, 0, 0.1);
    }

    .nav-links.active {
        right: 0;
    }

    .nav-links a {
        font-size: 1.1rem;
    }

    .about-grid {
        grid-template-columns: 1fr;
        gap: 36px;
    }

    .claude-features {
        grid-template-columns: 1fr;
    }

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

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

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

    .footer-top {
        flex-direction: column;
        gap: 24px;
        text-align: center;
    }

    .footer-brand {
        flex-direction: column;
        gap: 10px;
    }

    .section {
        padding: 72px 0;
    }
}

@media (max-width: 480px) {
    .hero h1 {
        font-size: 1.9rem;
    }

    .hero-tagline {
        font-size: 0.95rem;
    }

    .section-title {
        font-size: 1.6rem;
    }

    .btn {
        padding: 12px 24px;
        font-size: 0.92rem;
    }

    .join-buttons {
        flex-direction: column;
        align-items: center;
    }
}