/* ============================================
   Go Conference mini in Sendai 2026
   Modern Parallax Single Page Website
   ============================================ */

/* Variables */
:root {
    --primary-color: #00ADD8;
    --secondary-color: #5DC9E2;
    --accent-color: #00D4AA;
    --dark-color: #0A0E27;
    --light-color: #F8FAFC;
    --text-dark: #1A202C;
    --text-light: #718096;
    --sendai-green: #22C55E;
    --tanabata-purple: #8B5CF6;
    --shadow-sm: 0 2px 4px rgba(0,0,0,0.06);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.1);
    --shadow-lg: 0 10px 15px rgba(0,0,0,0.1);
    --shadow-xl: 0 20px 25px rgba(0,0,0,0.1);
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Reset & Base */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', 'Noto Sans JP', sans-serif;
    color: var(--text-dark);
    line-height: 1.6;
    overflow-x: hidden;
    background: var(--light-color);
}

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

/* Loader */
.loader {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100vh;
    background: linear-gradient(135deg, var(--primary-color), var(--tanabata-purple));
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 10000;
    transition: opacity 0.5s ease;
}

.loader.fade-out {
    opacity: 0;
    pointer-events: none;
}

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

.loader-spinner {
    width: 50px;
    height: 50px;
    border: 3px solid rgba(255, 255, 255, 0.3);
    border-top-color: white;
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto 20px;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

.loader p {
    color: white;
    font-size: 1.2rem;
    letter-spacing: 2px;
}

/* Progress Bar */
.progress-container {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 3px;
    background: rgba(0, 0, 0, 0.1);
    z-index: 1000;
}

.progress-bar {
    height: 100%;
    background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
    width: 0%;
    transition: width 0.1s ease;
}

/* Navigation */
.fixed-nav {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-md);
    z-index: 999;
    transition: var(--transition);
}

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

.nav-logo {
    font-size: 1.2rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary-color), var(--tanabata-purple));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-menu {
    display: flex;
    gap: 2rem;
}

.nav-link {
    text-decoration: none;
    color: var(--text-dark);
    font-weight: 500;
    position: relative;
    transition: var(--transition);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
    transition: width 0.3s ease;
}

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

/* Hero Section */
.hero {
    position: relative;
    height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 120%;
    background:
        linear-gradient(135deg, rgba(0, 173, 216, 0.8), rgba(139, 92, 246, 0.8)),
        linear-gradient(0deg, rgba(10, 14, 39, 0.9), transparent);
    z-index: -1;
}

.hero-bg::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image:
        radial-gradient(circle at 20% 50%, rgba(34, 197, 94, 0.3) 0%, transparent 50%),
        radial-gradient(circle at 80% 50%, rgba(0, 212, 170, 0.3) 0%, transparent 50%);
    animation: pulse 4s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 0.8; }
    50% { opacity: 1; }
}

.hero-content {
    text-align: center;
    z-index: 1;
    color: white;
}

.hero-title {
    margin-bottom: 2rem;
    animation: fadeInUp 1s ease;
}

.title-main {
    display: block;
    font-size: clamp(2rem, 5vw, 4rem);
    font-weight: 900;
    margin-bottom: 0.5rem;
    letter-spacing: 2px;
}

.title-sub {
    display: block;
    font-size: clamp(1.5rem, 3vw, 2.5rem);
    font-weight: 300;
    opacity: 0.9;
}

.hero-date {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    letter-spacing: 3px;
    animation: fadeInUp 1s ease 0.2s both;
}

.hero-venue {
    font-size: 1.2rem;
    margin-bottom: 3rem;
    opacity: 0.9;
    animation: fadeInUp 1s ease 0.4s both;
}

.hero-cta {
    display: flex;
    gap: 1rem;
    justify-content: center;
    animation: fadeInUp 1s ease 0.6s both;
}

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

/* Buttons */
.btn-primary,
.btn-secondary {
    padding: 1rem 2rem;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition);
    display: inline-block;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    color: white;
    box-shadow: 0 4px 15px rgba(0, 173, 216, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 173, 216, 0.4);
}

.btn-secondary {
    background: transparent;
    color: white;
    border: 2px solid white;
}

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

/* Scroll Indicator */
.scroll-indicator {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    animation: bounce 2s infinite;
}

.scroll-indicator span {
    display: block;
    width: 30px;
    height: 50px;
    margin: 0 auto 10px;
    border: 2px solid white;
    border-radius: 15px;
    position: relative;
}

.scroll-indicator span::after {
    content: '';
    position: absolute;
    top: 10px;
    left: 50%;
    transform: translateX(-50%);
    width: 4px;
    height: 10px;
    background: white;
    border-radius: 2px;
    animation: scroll 2s infinite;
}

.scroll-indicator p {
    color: white;
    font-size: 0.9rem;
    letter-spacing: 2px;
}

@keyframes bounce {
    0%, 100% { transform: translateX(-50%) translateY(0); }
    50% { transform: translateX(-50%) translateY(-10px); }
}

@keyframes scroll {
    0% { transform: translateX(-50%) translateY(0); opacity: 1; }
    100% { transform: translateX(-50%) translateY(15px); opacity: 0; }
}

/* Sections */
.section {
    padding: 100px 0;
    position: relative;
}

.fade-in-section {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.8s ease;
}

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

.section-header {
    text-align: center;
    margin-bottom: 3rem;
}

.section-title {
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 900;
    margin-bottom: 1rem;
    background: linear-gradient(135deg, var(--primary-color), var(--tanabata-purple));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.section-title-alt {
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 900;
    margin-bottom: 3rem;
    text-align: center;
    color: var(--text-dark);
    position: relative;
    display: inline-block;
    width: 100%;
}

.section-title-alt::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 100px;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
    border-radius: 2px;
}

.section-subtitle {
    font-size: 1.3rem;
    color: var(--text-light);
    font-weight: 500;
}

/* Theme Section */
.theme-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.theme-text p {
    font-size: 1.2rem;
    line-height: 1.8;
    margin-bottom: 2rem;
}

.theme-stats {
    display: flex;
    gap: 3rem;
    justify-content: center;
}

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

.stat-number {
    display: block;
    font-size: 3rem;
    font-weight: 900;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-label {
    display: block;
    color: var(--text-light);
    margin-top: 0.5rem;
}

.theme-visual {
    position: relative;
    height: 400px;
}

.visual-shape {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 300px;
    height: 300px;
    background: linear-gradient(135deg, var(--primary-color), var(--tanabata-purple));
    border-radius: 30% 70% 70% 30% / 30% 30% 70% 70%;
    animation: morph 8s ease-in-out infinite;
    opacity: 0.8;
}

@keyframes morph {
    0%, 100% { border-radius: 30% 70% 70% 30% / 30% 30% 70% 70%; }
    50% { border-radius: 70% 30% 30% 70% / 70% 70% 30% 30%; }
}

/* Overview Section */
.overview-section {
    background: linear-gradient(180deg, var(--light-color) 0%, white 100%);
}

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

.overview-card {
    background: white;
    padding: 2rem;
    border-radius: 20px;
    box-shadow: var(--shadow-lg);
    text-align: center;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.overview-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
}

.overview-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-xl);
}

.overview-card h3 {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

/* Timeline */
.schedule-section {
    background: white;
}

.timeline {
    position: relative;
    padding: 2rem 0;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 50%;
    top: 0;
    bottom: 0;
    width: 2px;
    background: linear-gradient(180deg, var(--primary-color), var(--tanabata-purple));
    transform: translateX(-50%);
}

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

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

.timeline-date {
    flex: 1;
    text-align: right;
    padding-right: 3rem;
    font-weight: 700;
    color: var(--primary-color);
    font-size: 1.2rem;
}

.timeline-item:nth-child(even) .timeline-date {
    text-align: left;
    padding-right: 0;
    padding-left: 3rem;
}

.timeline-content {
    flex: 1;
    background: white;
    padding: 1.5rem;
    border-radius: 15px;
    box-shadow: var(--shadow-lg);
    position: relative;
}

.timeline-content h3 {
    color: var(--text-dark);
    margin-bottom: 0.5rem;
}

.timeline-content p {
    color: var(--text-light);
}

.timeline-item::after {
    content: '';
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
    width: 20px;
    height: 20px;
    background: white;
    border: 4px solid var(--primary-color);
    border-radius: 50%;
}

/* Timetable */
.timetable-section {
    background: linear-gradient(180deg, white 0%, var(--light-color) 100%);
}

.timetable-wrapper {
    background: white;
    border-radius: 20px;
    padding: 2rem;
    box-shadow: var(--shadow-xl);
}

.timetable-header {
    text-align: center;
    margin-bottom: 2rem;
}

.timetable-header h3 {
    color: var(--text-dark);
    margin-bottom: 0.5rem;
}

.timetable-grid {
    display: grid;
    gap: 1rem;
}

.time-slot {
    display: grid;
    grid-template-columns: 150px 1fr auto;
    align-items: center;
    padding: 1rem;
    background: var(--light-color);
    border-radius: 10px;
    transition: var(--transition);
}

.time-slot:hover {
    transform: translateX(10px);
    box-shadow: var(--shadow-md);
}

.time-slot.keynote {
    background: linear-gradient(135deg, rgba(255, 215, 0, 0.1), rgba(255, 243, 224, 0.1));
    border-left: 4px solid gold;
}

.time-slot.sponsor {
    background: linear-gradient(135deg, rgba(139, 92, 246, 0.1), rgba(168, 85, 247, 0.1));
    border-left: 4px solid var(--tanabata-purple);
}

.time-slot.lunch,
.time-slot.break {
    background: linear-gradient(135deg, rgba(34, 197, 94, 0.1), rgba(74, 222, 128, 0.1));
    border-left: 4px solid var(--sendai-green);
}

.time-slot.lt {
    background: linear-gradient(135deg, rgba(0, 173, 216, 0.1), rgba(93, 201, 226, 0.1));
    border-left: 4px solid var(--primary-color);
}

.time-slot .time {
    font-weight: 600;
    color: var(--text-light);
}

.time-slot .title {
    font-weight: 600;
    color: var(--text-dark);
}

.time-slot .speaker {
    color: var(--primary-color);
    font-weight: 500;
}

/* Access Section */
.access-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    align-items: center;
}

.venue-option {
    background: white;
    padding: 1.5rem;
    border-radius: 15px;
    margin-bottom: 1rem;
    box-shadow: var(--shadow-md);
}

.venue-option h4 {
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.map-placeholder {
    background: linear-gradient(135deg, var(--primary-color), var(--tanabata-purple));
    height: 400px;
    border-radius: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.5rem;
    font-weight: 600;
    letter-spacing: 2px;
}

.map-container {
    margin-top: 2rem;
    border-radius: 20px;
    overflow: hidden;
    box-shadow: var(--shadow-lg);
}

.map-container iframe {
    display: block;
}

/* Sponsor Section */
.sponsor-section {
    background: linear-gradient(135deg, var(--primary-color), var(--tanabata-purple));
    color: white;
}

.sponsor-section .section-title-alt {
    color: white;
}

.sponsor-section .section-title-alt::after {
    background: white;
}

.sponsor-tier {
    margin-bottom: 3rem;
}

.sponsor-tier-title {
    text-align: center;
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    opacity: 0.9;
}

.sponsor-logos {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 2rem;
    flex-wrap: wrap;
}

.sponsor-logos.platinum .sponsor-logo-placeholder,
.sponsor-logos.platinum .sponsor-logo {
    width: 350px;
    height: 200px;
}

.sponsor-logos.gold .sponsor-logo-placeholder,
.sponsor-logos.gold .sponsor-logo {
    width: 280px;
    height: 160px;
}

.sponsor-logos.silver .sponsor-logo-placeholder,
.sponsor-logos.silver .sponsor-logo {
    width: 220px;
    height: 130px;
}

.sponsor-logos.community .sponsor-logo-placeholder,
.sponsor-logos.community .sponsor-logo {
    width: 180px;
    height: 100px;
}

.sponsor-logos.venue .sponsor-logo-placeholder,
.sponsor-logos.venue .sponsor-logo {
    width: 280px;
    height: 160px;
}

.sponsor-logo-placeholder {
    background: rgba(255, 255, 255, 0.1);
    border: 2px dashed rgba(255, 255, 255, 0.4);
    border-radius: 15px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

.sponsor-logo-placeholder:hover {
    background: rgba(255, 255, 255, 0.15);
    border-color: rgba(255, 255, 255, 0.6);
}

.sponsor-logo-placeholder p {
    color: rgba(255, 255, 255, 0.7);
    font-size: 1.1rem;
    font-weight: 600;
}

.sponsor-logo {
    background: white;
    border-radius: 15px;
    padding: 1.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

.sponsor-logo:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
}

.sponsor-logo img {
    max-width: 100%;
    max-height: 100%;
    object-fit: contain;
}

.sponsor-cta {
    margin-top: 4rem;
    text-align: center;
}

.sponsor-text {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    line-height: 1.8;
}

.sponsor-section .btn-primary {
    background: white;
    color: var(--primary-color);
}

/* CoC Section */
.coc-section {
    text-align: center;
}

.coc-section p {
    font-size: 1.1rem;
    line-height: 1.8;
    margin-bottom: 2rem;
}

.link-external {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition);
}

.link-external:hover {
    text-decoration: underline;
}

/* Footer */
.footer {
    background: var(--dark-color);
    color: white;
    padding: 3rem 0 1rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer h3,
.footer h4 {
    margin-bottom: 1rem;
}

.footer a {
    color: var(--secondary-color);
    text-decoration: none;
    display: block;
    margin-bottom: 0.5rem;
    transition: var(--transition);
}

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

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    opacity: 0.7;
}

/* Responsive */
@media (max-width: 768px) {
    .nav-menu {
        gap: 1rem;
        font-size: 0.9rem;
    }

    .theme-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .theme-stats {
        flex-direction: column;
        gap: 1.5rem;
    }

    .timeline::before {
        left: 20px;
    }

    .timeline-item {
        flex-direction: column;
        align-items: flex-start;
        margin-left: 50px;
        margin-bottom: 4rem;
    }

    .timeline-item:nth-child(even) {
        flex-direction: column;
    }

    .timeline-date {
        text-align: left !important;
        padding: 0 0 0.5rem 0 !important;
        font-size: 1rem;
        margin-left: -30px;
    }

    .timeline-content {
        width: calc(100% - 20px);
    }

    .timeline-item::after {
        display: none;
    }

    .time-slot {
        grid-template-columns: 1fr;
        gap: 0.5rem;
    }

    .access-content {
        grid-template-columns: 1fr;
    }

    .sponsor-logos.platinum .sponsor-logo-placeholder,
    .sponsor-logos.platinum .sponsor-logo {
        width: 280px;
        height: 160px;
    }

    .sponsor-logos.gold .sponsor-logo-placeholder,
    .sponsor-logos.gold .sponsor-logo {
        width: 240px;
        height: 140px;
    }

    .sponsor-logos.silver .sponsor-logo-placeholder,
    .sponsor-logos.silver .sponsor-logo {
        width: 200px;
        height: 120px;
    }

    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
}

@media (max-width: 480px) {
    .hero-cta {
        flex-direction: column;
        width: 100%;
        padding: 0 20px;
    }

    .btn-primary,
    .btn-secondary {
        width: 100%;
    }

    .nav-menu {
        display: none;
    }
}