/* ===== INDEX PAGE STYLES ===== */

html { scroll-behavior: smooth; }
body { overflow-x: hidden; }

/* Glow utilities */
.glow-pink { color: var(--neon-pink); }
.glow-cyan { color: var(--neon-cyan); }
.glow-purple { color: var(--neon-purple); }

/* Nav overrides for index (animated reveal) */
.nav-bar {
    opacity: 0;
    transform: translateY(-20px);
}

body.loaded .nav-bar {
    opacity: 1; transform: translateY(0);
    transition: opacity 600ms var(--ease-out-expo) 200ms, transform 600ms var(--ease-out-expo) 200ms;
}

.nav-accent-line {
    opacity: 0; transform: scaleX(0); transform-origin: left;
}

body.loaded .nav-accent-line {
    opacity: 0.4; transform: scaleX(1);
    transition: opacity 400ms ease 400ms, transform 800ms var(--ease-out-expo) 400ms;
}

/* ===== HERO ===== */
.hero {
    position: relative; z-index: 1;
    min-height: 100vh; display: flex; align-items: center;
    padding: 0 4rem; padding-top: 70px;
}

.hero-bg { position: fixed; inset: 0; z-index: 0; }

.hero-bg-img {
    position: absolute; inset: 0;
    background: url('../picture/background.jpg') center center / cover no-repeat;
    opacity: 0; transition: opacity 800ms ease;
}

body.loaded .hero-bg-img { opacity: 1; }

.hero-bg-overlay {
    position: absolute; inset: 0;
    background:
        radial-gradient(ellipse at center, transparent 30%, rgba(5,0,10,0.4) 100%),
        linear-gradient(to top, rgba(5,0,10,0.85) 0%, rgba(5,0,10,0.15) 25%, transparent 50%),
        linear-gradient(to right, rgba(5,0,10,0.55) 0%, rgba(5,0,10,0.1) 40%, transparent 60%),
        linear-gradient(to bottom, rgba(5,0,10,0.35) 0%, transparent 10%);
}

/* Particles */
.particles { position: fixed; inset: 0; z-index: 0; pointer-events: none; }

.p {
    position: absolute; border-radius: 50%; pointer-events: none;
    opacity: 0; animation: pfloat linear infinite;
}

.p:nth-child(1) { width: 3px; height: 3px; left: 10%; bottom: 0; background: rgba(166,110,247,0.6); animation-duration: 14s; animation-delay: 0s; }
.p:nth-child(2) { width: 2px; height: 2px; left: 35%; bottom: 0; background: rgba(92,200,223,0.5); animation-duration: 18s; animation-delay: 3s; }
.p:nth-child(3) { width: 3px; height: 3px; left: 60%; bottom: 0; background: rgba(224,96,154,0.5); animation-duration: 16s; animation-delay: 6s; }
.p:nth-child(4) { width: 2px; height: 2px; left: 82%; bottom: 0; background: rgba(74,222,128,0.5); animation-duration: 20s; animation-delay: 1s; }

@keyframes pfloat {
    0% { transform: translateY(0) scale(0); opacity: 0; }
    6% { opacity: 0.9; transform: translateY(-4vh) scale(1); }
    50% { opacity: 0.4; }
    100% { transform: translateY(-110vh) scale(0.3); opacity: 0; }
}

.hero-content { max-width: 680px; position: relative; z-index: 2; }

.hero-badge {
    display: inline-flex; align-items: center; gap: 8px;
    padding: 8px 18px;
    border: 1px solid rgba(255, 255, 255, 0.12);
    border-radius: 20px;
    color: rgba(255, 255, 255, 0.8);
    font-family: var(--font-display); font-size: 0.6rem; font-weight: 600;
    letter-spacing: 0.3em; text-transform: uppercase;
    background: linear-gradient(135deg, rgba(166,110,247,0.15), rgba(92,200,223,0.1));
    -webkit-backdrop-filter: blur(12px); backdrop-filter: blur(12px);
    margin-bottom: 1.5rem;
    opacity: 0; transform: translateY(20px);
}

.hero-badge .badge-dot {
    width: 6px; height: 6px; border-radius: 50%;
    background: var(--neon-green);
    animation: dot-pulse 2s ease-in-out infinite;
}

@keyframes dot-pulse {
    0%, 100% { opacity: 1; transform: scale(1); }
    50% { opacity: 0.4; transform: scale(0.7); }
}

body.loaded .hero-badge {
    opacity: 1; transform: translateY(0);
    transition: opacity 500ms var(--ease-out-expo) 500ms, transform 500ms var(--ease-out-expo) 500ms;
}

.hero-title { font-family: var(--font-display); font-weight: 900; line-height: 1.05; margin-bottom: 1.5rem; }

.title-line {
    display: block; font-size: 4rem; letter-spacing: 0.06em;
    opacity: 0; transform: translateY(40px);
}

.title-line-1 { color: var(--white); }

.title-line-2 {
    background: linear-gradient(90deg, #f7a44c, #e0609a);
    -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
}

body.loaded .title-line-1 { opacity: 1; transform: translateY(0); transition: opacity 700ms var(--ease-out-expo) 700ms, transform 700ms var(--ease-out-expo) 700ms; }
body.loaded .title-line-2 { opacity: 1; transform: translateY(0); transition: opacity 700ms var(--ease-out-expo) 900ms, transform 700ms var(--ease-out-expo) 900ms; }

.hero-subtitle {
    font-family: var(--font-body); font-size: 1.15rem; font-weight: 400;
    color: var(--muted); line-height: 1.8; margin-bottom: 2.5rem; max-width: 500px;
    opacity: 0;
}

body.loaded .hero-subtitle { opacity: 1; transition: opacity 500ms ease 1100ms; }

.hero-actions { display: flex; align-items: center; gap: 2rem; flex-wrap: wrap; }

/* ===== CTA BUTTON ===== */
.cta-btn {
    position: relative; display: inline-flex; align-items: center; gap: 12px;
    padding: 16px 40px;
    background: linear-gradient(135deg, rgba(166,110,247,0.3), rgba(92,200,223,0.2));
    color: var(--white);
    border: 1px solid rgba(255, 255, 255, 0.15);
    border-radius: 14px; cursor: pointer;
    font-family: var(--font-display); font-size: 0.85rem; font-weight: 700;
    letter-spacing: 0.12em; text-transform: uppercase; text-decoration: none;
    -webkit-backdrop-filter: blur(16px); backdrop-filter: blur(16px);
    transition: all 400ms var(--ease-out-expo);
    opacity: 0; transform: scale(0.95); overflow: hidden;
}

body.loaded .cta-btn {
    opacity: 1; transform: scale(1);
    transition: opacity 600ms var(--ease-out-back) 1300ms, transform 600ms var(--ease-out-back) 1300ms, background 300ms ease, border-color 300ms ease, box-shadow 400ms ease;
}

.cta-btn:hover {
    background: linear-gradient(135deg, rgba(166,110,247,0.5), rgba(92,200,223,0.35));
    border-color: rgba(255, 255, 255, 0.25);
    box-shadow: 0 8px 32px rgba(166,110,247,0.2);
    transform: translateY(-2px) scale(1.02);
}

.cta-btn:active { transform: scale(0.97) !important; }

.cta-btn::before {
    content: ''; position: absolute; top: 0; left: -100%; width: 50%; height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
    transform: skewX(-20deg); transition: left 0.5s var(--ease-out-expo);
}

.cta-btn:hover::before { left: 130%; }
.cta-btn svg { width: 18px; height: 18px; flex-shrink: 0; }

.secondary-link {
    color: var(--muted); text-decoration: none;
    font-family: var(--font-display); font-size: 0.7rem; font-weight: 600;
    letter-spacing: 0.1em; text-transform: uppercase;
    transition: color 300ms ease; opacity: 0;
}

body.loaded .secondary-link { opacity: 1; transition: opacity 400ms ease 1500ms, color 300ms ease, text-shadow 300ms ease; }
.secondary-link:hover { color: var(--white); }

.secondary-link .arrow {
    display: inline-block; margin-left: 6px;
    animation: bounce-arrow 2s ease-in-out infinite;
}

@keyframes bounce-arrow { 0%, 100% { transform: translateY(0); } 50% { transform: translateY(5px); } }

/* ===== SECTION DIVIDER ===== */
.section-divider {
    position: relative; z-index: 3; height: 1px;
    background: linear-gradient(90deg, transparent, rgba(166,110,247,0.3) 20%, rgba(224,96,154,0.25) 50%, rgba(92,200,223,0.3) 80%, transparent);
}

/* ===== ABOUT ===== */
.section-about {
    position: relative; z-index: 2;
    min-height: 100vh; display: flex; align-items: center; overflow: hidden;
}

.about-bg {
    position: absolute; inset: 0;
    background: url('../picture/background1.png') center center / cover no-repeat;
}

.about-bg-overlay {
    position: absolute; inset: 0;
    background:
        linear-gradient(to bottom, var(--bg-black) 0%, rgba(5,0,10,0.55) 18%, rgba(5,0,10,0.5) 75%, var(--bg-black) 100%),
        radial-gradient(ellipse at 60% 40%, rgba(191,0,255,0.06) 0%, transparent 50%),
        radial-gradient(ellipse at 20% 80%, rgba(0,240,255,0.04) 0%, transparent 40%);
}

.about-content {
    position: relative; z-index: 2;
    width: 100%; max-width: 1200px; margin: 0 auto;
    padding: 6rem 4rem;
    display: flex; flex-direction: column;
    gap: 3rem; align-items: center; text-align: center;
}

.about-label {
    display: inline-flex; align-items: center; gap: 8px;
    padding: 6px 16px;
    border: 1px solid rgba(255, 255, 255, 0.1); border-radius: 16px;
    color: rgba(255, 255, 255, 0.7);
    font-family: var(--font-display); font-size: 0.55rem; font-weight: 600;
    letter-spacing: 0.25em; text-transform: uppercase;
    background: linear-gradient(135deg, rgba(224,96,154,0.12), rgba(166,110,247,0.08));
    margin-bottom: 1.5rem;
}

.about-title {
    font-family: var(--font-display); font-size: 2.4rem; font-weight: 800;
    line-height: 1.2; margin-bottom: 1.5rem; letter-spacing: 0.03em;
}

.about-title .neon-text {
    background: linear-gradient(90deg, var(--neon-cyan), var(--neon-green));
    -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
}

.about-desc {
    font-size: 1.05rem; color: var(--muted); line-height: 1.9;
    margin-bottom: 2.2rem; font-weight: 400;
}

.about-stats { display: flex; gap: 2.5rem; }
.stat-item { position: relative; padding-left: 14px; }

.stat-item::before {
    content: ''; position: absolute; left: 0; top: 4px; bottom: 4px; width: 3px;
    background: linear-gradient(to bottom, var(--neon-purple), var(--neon-cyan));
    border-radius: 2px;
}

.stat-number {
    font-family: var(--font-display); font-size: 1.8rem; font-weight: 800;
    line-height: 1; margin-bottom: 0.3rem;
    background: linear-gradient(135deg, var(--neon-cyan), var(--neon-green));
    -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
}

.stat-label {
    font-size: 0.72rem; color: var(--muted);
    letter-spacing: 0.08em; text-transform: uppercase; font-weight: 600;
}

.about-text-side { max-width: 700px; }
.about-features-side { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.2rem; width: 100%; }

.about-feature-card {
    position: relative;
    background: linear-gradient(135deg, rgba(255,255,255,0.07), rgba(255,255,255,0.02));
    -webkit-backdrop-filter: blur(16px); backdrop-filter: blur(16px);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: 16px; padding: 1.4rem 1.6rem;
    display: flex; gap: 1rem; align-items: flex-start;
    cursor: default;
    transition: transform 400ms var(--ease-spring), border-color 400ms ease, background 400ms ease;
    opacity: 0; transform: translateY(25px); overflow: hidden;
}

.about-feature-card:hover {
    transform: translateY(-4px);
    border-color: rgba(255, 255, 255, 0.18);
    background: linear-gradient(135deg, rgba(255,255,255,0.1), rgba(255,255,255,0.04));
}

.about-feature-card.visible {
    opacity: 1; transform: translateY(0);
    transition: opacity 600ms var(--ease-out-expo), transform 600ms var(--ease-out-expo), border-color 400ms ease, background 400ms ease;
}

.about-feature-card:nth-child(1).visible { transition-delay: 0ms; }
.about-feature-card:nth-child(2).visible { transition-delay: 150ms; }
.about-feature-card:nth-child(3).visible { transition-delay: 300ms; }
.about-feature-card:nth-child(4).visible { transition-delay: 450ms; }
.about-feature-card:nth-child(5).visible { transition-delay: 600ms; }
.about-feature-card:nth-child(6).visible { transition-delay: 750ms; }

.about-feature-icon { width: 36px; height: 36px; flex-shrink: 0; color: var(--neon-cyan); }
.about-feature-icon svg { width: 100%; height: 100%; }

.about-feature-card h3 {
    font-family: var(--font-display); font-size: 0.85rem; font-weight: 700;
    margin-bottom: 0.3rem; letter-spacing: 0.04em; color: var(--white);
}

.about-feature-card p { font-size: 0.82rem; color: var(--muted); line-height: 1.6; }

/* ===== DOWNLOAD ===== */
.section-download {
    position: relative; z-index: 2;
    min-height: 100vh; display: flex; align-items: center; justify-content: center;
    overflow: hidden;
}

.download-bg {
    position: absolute; inset: 0;
    background: url('../picture/background2.png') center center / cover no-repeat;
}

.download-bg-overlay {
    position: absolute; inset: 0;
    background:
        linear-gradient(to bottom, var(--bg-black) 0%, rgba(5,0,10,0.8) 15%, rgba(5,0,10,0.75) 85%, var(--bg-black) 100%),
        radial-gradient(circle at 50% 50%, rgba(191,0,255,0.08) 0%, transparent 50%);
}

.download-content {
    position: relative; z-index: 2;
    text-align: center; max-width: 700px; padding: 4rem 2rem;
}

.download-logo {
    width: 110px; height: auto; margin-bottom: 2rem;
    filter: drop-shadow(0 0 10px rgba(166,110,247,0.3));
    opacity: 0; transform: scale(0.7) rotate(-5deg); animation: none;
}

.download-logo.visible {
    opacity: 1; transform: scale(1) rotate(0);
    transition: opacity 800ms var(--ease-out-back), transform 800ms var(--ease-out-back);
}

.download-title {
    font-family: var(--font-display); font-size: 2.4rem; font-weight: 900;
    margin-bottom: 0.8rem; letter-spacing: 0.05em;
}

.download-subtitle {
    font-size: 1.05rem; color: var(--muted); font-weight: 400;
    line-height: 1.7; margin-bottom: 2.5rem;
    max-width: 520px; margin-left: auto; margin-right: auto;
}

.download-btn {
    position: relative; display: inline-flex; align-items: center; gap: 14px;
    padding: 18px 52px;
    background: linear-gradient(135deg, var(--neon-purple), var(--neon-pink), var(--neon-cyan));
    background-size: 200% 200%;
    animation: btn-gradient 6s ease infinite;
    color: var(--white); border: none; border-radius: 16px;
    cursor: pointer; font-family: var(--font-display); overflow: hidden;
    box-shadow: 0 8px 32px rgba(166,110,247,0.25);
    transition: transform 400ms var(--ease-spring), box-shadow 400ms ease;
    opacity: 0; transform: translateY(20px);
}

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

.download-btn.visible {
    opacity: 1; transform: translateY(0);
    transition: opacity 600ms var(--ease-out-back) 200ms, transform 600ms var(--ease-out-back) 200ms, box-shadow 400ms ease;
}

.download-btn:hover {
    transform: translateY(-4px) scale(1.04);
    box-shadow: 0 12px 40px rgba(166,110,247,0.35), 0 4px 16px rgba(0,0,0,0.3);
}

.download-btn:active { transform: scale(0.96) !important; }

.download-btn::before {
    content: ''; position: absolute; top: 0; left: -100%; width: 50%; height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.25), transparent);
    transform: skewX(-20deg); transition: left 0.5s var(--ease-out-expo);
}

.download-btn:hover::before { left: 130%; }

.download-btn::after {
    content: ''; position: absolute; bottom: 0; left: 0;
    width: 0; height: 3px; border-radius: 2px;
    background: linear-gradient(90deg, rgba(255,255,255,0.4), rgba(255,255,255,0.8));
}

.download-btn.downloading::after { animation: dl-progress 2s var(--ease-out-expo) forwards; }
@keyframes dl-progress { from { width: 0; } to { width: 100%; } }

.btn-icon { display: flex; align-items: center; flex-shrink: 0; }
.btn-icon svg { width: 22px; height: 22px; }
.btn-text { display: flex; flex-direction: column; text-align: left; }
.btn-label { font-size: 1.1rem; font-weight: 700; letter-spacing: 0.06em; }
.btn-meta { font-family: var(--font-body); font-size: 0.72rem; font-weight: 500; color: rgba(255,255,255,0.6); margin-top: 2px; }

.download-platforms {
    margin-top: 2rem; display: flex; justify-content: center; gap: 1.8rem; opacity: 0;
}

.download-platforms.visible { opacity: 1; transition: opacity 500ms ease 400ms; }

.platform-tag {
    display: flex; align-items: center; gap: 6px;
    font-size: 0.75rem; color: var(--muted); font-weight: 500;
    padding: 8px 16px; border: 1px solid rgba(255,255,255,0.08);
    border-radius: 10px; background: rgba(255,255,255,0.04);
    -webkit-backdrop-filter: blur(8px); backdrop-filter: blur(8px);
    transition: border-color 300ms ease, color 300ms ease, background 300ms ease;
}

.platform-tag:hover {
    border-color: rgba(255, 255, 255, 0.2); color: var(--white);
    background: rgba(255,255,255,0.08);
}

.platform-tag svg { width: 14px; height: 14px; opacity: 0.7; }

.download-version-info {
    margin-top: 1.5rem; font-size: 0.68rem; font-family: var(--font-display);
    color: rgba(122, 108, 153, 0.4); letter-spacing: 0.06em; opacity: 0;
}

.download-version-info.visible { opacity: 1; transition: opacity 500ms ease 600ms; }

/* ===== FOOTER ===== */
.site-footer {
    position: relative; z-index: 2;
    background: var(--bg-black);
    border-top: 1px solid rgba(255,255,255,0.05);
    padding: 1.5rem 4rem; text-align: center;
}

.site-footer p {
    font-size: 0.68rem; color: rgba(122, 108, 153, 0.5);
    font-family: var(--font-display); letter-spacing: 0.08em;
}

/* ===== SCROLL REVEAL ===== */
.reveal-up { opacity: 0; transform: translateY(25px); }
.reveal-up.visible {
    opacity: 1; transform: translateY(0);
    transition: opacity 600ms var(--ease-out-expo), transform 600ms var(--ease-out-expo);
}

.reveal-up:nth-child(1).visible { transition-delay: 0ms; }
.reveal-up:nth-child(2).visible { transition-delay: 120ms; }
.reveal-up:nth-child(3).visible { transition-delay: 240ms; }
.reveal-up:nth-child(4).visible { transition-delay: 360ms; }

/* ===== RESPONSIVE ===== */
@media (max-width: 1024px) {
    .hero { padding: 70px 3rem 0; }
    .title-line { font-size: 3rem; }
    .nav-links { gap: 1.5rem; }
    .about-content { gap: 2.5rem; padding: 5rem 3rem; }
    .about-features-side { grid-template-columns: 1fr 1fr; }
    .about-title { font-size: 2rem; }
    .download-title { font-size: 2rem; }
}

@media (max-width: 768px) {
    .hero { padding: 70px 1.5rem 0; }
    .hero-content { max-width: 100%; text-align: center; }
    .title-line { font-size: 2.4rem; }
    .hero-subtitle { max-width: 100%; }
    .hero-actions { flex-direction: column; align-items: center; gap: 1.2rem; }
    .cta-btn { width: 100%; max-width: 320px; justify-content: center; font-size: 0.75rem; }
    .hero-bg-img { background-position: 70% center; }

    .about-content { padding: 4rem 1.5rem; gap: 2rem; }
    .about-features-side { grid-template-columns: 1fr; }
    .about-title { font-size: 1.8rem; }
    .about-stats { justify-content: center; }
    .stat-item { text-align: center; }
    .stat-item::before { display: none; }

    .download-content { padding: 3rem 1.5rem; }
    .download-title { font-size: 1.8rem; }
    .download-btn { width: 100%; max-width: 340px; justify-content: center; }
    .download-platforms { gap: 0.8rem; flex-wrap: wrap; }
    .site-footer { padding: 1.5rem; }
}

@media (max-width: 480px) {
    .title-line { font-size: 1.9rem; }
    .hero-badge { font-size: 0.5rem; padding: 5px 10px; letter-spacing: 0.2em; }
    .hero-subtitle { font-size: 1rem; }
    .about-title { font-size: 1.5rem; }
    .about-stats { flex-direction: column; gap: 1rem; }
    .download-title { font-size: 1.5rem; }
    .download-logo { width: 80px; }
}

/* Index scrollbar overrides */
::-webkit-scrollbar { width: 4px; }
::-webkit-scrollbar-track { background: var(--bg-black); }
::-webkit-scrollbar-thumb { background: rgba(166,110,247,0.4); border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: rgba(166,110,247,0.6); }

/* ===== BGM TOGGLE ===== */
.bgm-toggle {
    position: fixed; bottom: 24px; right: 24px; z-index: 999;
    width: 42px; height: 42px; border-radius: 50%;
    background: linear-gradient(135deg, rgba(166,110,247,0.4), rgba(92,200,223,0.3));
    -webkit-backdrop-filter: blur(20px); backdrop-filter: blur(20px);
    border: 1px solid rgba(255,255,255,0.12);
    color: var(--white); cursor: pointer;
    display: none; align-items: center; justify-content: center;
    box-shadow: 0 4px 20px rgba(0,0,0,0.3);
    transition: all 300ms ease;
    opacity: 0; transform: scale(0.8);
}

.bgm-toggle.visible {
    display: flex;
    opacity: 1; transform: scale(1);
}

.bgm-toggle:hover {
    border-color: rgba(255,255,255,0.25);
    box-shadow: 0 4px 24px rgba(166,110,247,0.3);
    transform: scale(1.1);
}

.bgm-toggle svg { width: 18px; height: 18px; }
.bgm-toggle .bgm-icon-off { display: none; }
.bgm-toggle.muted .bgm-icon-on { display: none; }
.bgm-toggle.muted .bgm-icon-off { display: block; }

.bgm-toggle.playing { animation: bgm-pulse 2s ease-in-out infinite; }

@keyframes bgm-pulse {
    0%, 100% { box-shadow: 0 4px 20px rgba(0,0,0,0.3); }
    50% { box-shadow: 0 4px 28px rgba(166,110,247,0.45); }
}

@media (max-width: 480px) {
    .bgm-toggle { bottom: 16px; right: 16px; width: 38px; height: 38px; }
}