/* ===== mmd-player landing page — modern / clean / premium ===== */
:root {
  --bg: #0b0d14;
  --bg-soft: #10131d;
  --panel: #141827;
  --panel-2: #1a1f30;
  --border: #242a3f;
  --text: #eef1f8;
  --text-dim: #9aa3bd;
  --accent: #6c7bff;
  --accent-2: #22d3ee;
  --grad: linear-gradient(135deg, #6c7bff 0%, #22d3ee 100%);
  --radius: 18px;
  --container: 1120px;
  --ease: cubic-bezier(.22, .61, .36, 1);
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", -apple-system, BlinkMacSystemFont, "Helvetica Neue", Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

a { color: inherit; text-decoration: none; }

/* ---------- Navbar ---------- */
.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  background: rgba(11, 13, 20, .72);
  border-bottom: 1px solid rgba(36, 42, 63, .6);
}
.nav-inner {
  max-width: var(--container);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 24px;
}
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; letter-spacing: .3px; }
.brand-mark {
  width: 26px; height: 26px;
  border-radius: 8px;
  background: var(--grad);
  position: relative;
  box-shadow: 0 4px 18px rgba(108, 123, 255, .45);
}
.brand-mark::after {
  content: "▶";
  position: absolute; inset: 0;
  display: grid; place-items: center;
  font-size: 10px; color: #fff;
}
.nav-links { display: flex; gap: 28px; font-size: 14.5px; color: var(--text-dim); }
.nav-links a { transition: color .25s var(--ease); }
.nav-links a:hover { color: var(--text); }
.lang-wrap { display: flex; align-items: center; }
.lang-select {
  appearance: none;
  -webkit-appearance: none;
  background: rgba(255, 255, 255, .04);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 7px 30px 7px 14px;
  font-size: 13.5px;
  font-family: inherit;
  cursor: pointer;
  background-image: url("data:image/svg+xml;charset=utf-8,%3Csvg xmlns='http://www.w3.org/2000/svg' width='10' height='6' fill='%239aa3bd'%3E%3Cpath d='M1 1l4 4 4-4' stroke='%239aa3bd' stroke-width='1.5' fill='none' stroke-linecap='round'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
  transition: border-color .25s var(--ease);
}
.lang-select:hover, .lang-select:focus { border-color: var(--accent); outline: none; }
.lang-select option { background: var(--panel-2); color: var(--text); }
.nav-toggle {
  display: none;
  flex-direction: column; gap: 5px;
  background: none; border: 0; cursor: pointer;
  padding: 6px;
}
.nav-toggle span { width: 22px; height: 2px; background: var(--text); border-radius: 2px; transition: .3s var(--ease); }
.nav-toggle.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.open span:nth-child(2) { opacity: 0; }
.nav-toggle.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ---------- Hero ---------- */
.hero {
  position: relative;
  padding: 120px 24px 80px;
  text-align: center;
  overflow: hidden;
}
.hero-glow {
  position: absolute;
  border-radius: 50%;
  filter: blur(120px);
  opacity: .5;
  pointer-events: none;
}
.hero-glow-a { width: 480px; height: 480px; background: rgba(108, 123, 255, .28); top: -160px; left: -100px; }
.hero-glow-b { width: 420px; height: 420px; background: rgba(34, 211, 238, .22); bottom: -160px; right: -80px; }
.hero-inner { position: relative; max-width: 820px; margin: 0 auto; }
.hero-eyebrow {
  display: inline-block;
  font-size: 12px; letter-spacing: 3px; color: var(--accent-2);
  border: 1px solid rgba(34, 211, 238, .35);
  background: rgba(34, 211, 238, .07);
  padding: 6px 16px; border-radius: 999px;
  margin-bottom: 28px;
}
.hero-title { font-size: clamp(40px, 6vw, 68px); line-height: 1.15; font-weight: 800; letter-spacing: .5px; }
.grad-text { background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero-sub {
  margin: 26px auto 0; max-width: 640px;
  color: var(--text-dim); font-size: 17px;
}
.hero-actions { margin-top: 40px; display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }
.hero-stats {
  margin: 64px auto 0;
  display: flex; justify-content: center; gap: 64px; flex-wrap: wrap;
}
.stat { display: flex; flex-direction: column; gap: 4px; }
.stat strong { font-size: 34px; font-weight: 800; background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.stat span { font-size: 13px; color: var(--text-dim); }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  padding: 13px 30px; border-radius: 12px;
  font-size: 15px; font-weight: 600;
  transition: transform .25s var(--ease), box-shadow .25s var(--ease), border-color .25s var(--ease), background .25s var(--ease);
}
.btn-primary {
  background: var(--grad); color: #fff;
  box-shadow: 0 8px 30px rgba(108, 123, 255, .35);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 14px 40px rgba(108, 123, 255, .5); }
.btn-ghost {
  border: 1px solid var(--border); color: var(--text);
  background: rgba(255, 255, 255, .02);
}
.btn-ghost:hover { border-color: var(--accent); transform: translateY(-2px); }

/* ---------- Sections ---------- */
.section { padding: 96px 24px; }
.section-alt { background: var(--bg-soft); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }
.section-head { text-align: center; max-width: 640px; margin: 0 auto 56px; }
.section-eyebrow { font-size: 12px; letter-spacing: 3px; color: var(--accent); text-transform: uppercase; margin-bottom: 12px; }
.section-title { font-size: clamp(30px, 4vw, 42px); font-weight: 800; letter-spacing: .3px; }
.section-desc { margin-top: 14px; color: var(--text-dim); }

/* ---------- Feature cards ---------- */
.feature-grid {
  max-width: var(--container); margin: 0 auto;
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px;
}
.card {
  background: linear-gradient(180deg, var(--panel) 0%, rgba(20, 24, 39, .6) 100%);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 24px;
  transition: transform .35s var(--ease), border-color .35s var(--ease), box-shadow .35s var(--ease);
}
.card:hover { transform: translateY(-6px); border-color: rgba(108, 123, 255, .55); box-shadow: 0 18px 50px rgba(0, 0, 0, .45); }
.card-icon {
  width: 46px; height: 46px; border-radius: 13px;
  display: grid; place-items: center;
  font-size: 20px; color: #fff;
  background: var(--grad);
  margin-bottom: 18px;
  box-shadow: 0 6px 20px rgba(108, 123, 255, .35);
}
.card h3 { font-size: 17px; margin-bottom: 10px; }
.card p { font-size: 14px; color: var(--text-dim); }

/* ---------- Tech ---------- */
.tech-wrap { max-width: var(--container); margin: 0 auto; display: grid; grid-template-columns: 2fr 1fr; gap: 24px; align-items: start; }
.tech-main { display: grid; gap: 20px; }
.tech-card h3 { font-size: 15px; margin-bottom: 8px; color: var(--accent-2); letter-spacing: .5px; }
.tech-card p { font-size: 14px; color: var(--text-dim); }
.tech-stack {
  display: flex; flex-wrap: wrap; gap: 12px; align-content: flex-start;
  position: sticky; top: 96px;
}
.tech-stack span {
  font-size: 13px; font-weight: 600;
  padding: 8px 16px; border-radius: 999px;
  background: rgba(20, 24, 39, .8); border: 1px solid var(--border);
  color: var(--text);
  transition: .3s var(--ease);
}
.tech-stack span:hover { border-color: var(--accent); transform: translateY(-2px); }

/* ---------- Intro ---------- */
.intro-card {
  max-width: 860px;
  margin: 0 auto;
  padding: 48px 52px;
  border-radius: var(--radius);
  background: linear-gradient(180deg, var(--panel) 0%, rgba(20, 24, 39, .6) 100%);
  border: 1px solid var(--border);
  box-shadow: 0 30px 90px rgba(0, 0, 0, .4);
}
.intro-card p {
  font-size: 15px;
  line-height: 2;
  color: var(--text-dim);
  margin-bottom: 18px;
}
.intro-card p:last-of-type { margin-bottom: 28px; }
.intro-lead {
  font-size: 17px !important;
  color: var(--text) !important;
  border-left: 3px solid transparent;
  border-image: var(--grad);
  border-image-slice: 1;
  padding-left: 16px;
}
.intro-contact {
  display: flex;
  align-items: center;
  gap: 14px;
  flex-wrap: wrap;
  padding: 16px 20px;
  border-radius: 12px;
  background: rgba(108, 123, 255, .08);
  border: 1px solid rgba(108, 123, 255, .25);
}
.intro-contact-label {
  font-size: 13px;
  color: var(--text-dim);
  letter-spacing: 1px;
}
.intro-contact-mail {
  font-size: 15px;
  font-weight: 600;
  color: var(--accent-2);
  text-decoration: none;
  transition: color .25s var(--ease);
}
.intro-contact-mail:hover { color: var(--accent); }
.i18n-link {
  color: var(--accent-2);
  text-decoration: none;
  border-bottom: 1px dashed rgba(34, 211, 238, .5);
  transition: color .25s var(--ease), border-color .25s var(--ease);
}
.i18n-link:hover { color: var(--accent); border-bottom-color: var(--accent); }

/* ---------- About ---------- */
.about-inner {
  max-width: var(--container); margin: 0 auto;
  display: flex; align-items: flex-end; justify-content: space-between;
  gap: 24px; flex-wrap: wrap;
}
.about-chips { display: flex; gap: 14px; flex-wrap: wrap; }
.quote {
  max-width: var(--container); margin: 60px auto 0;
  text-align: center;
  font-size: clamp(20px, 3vw, 28px);
  font-weight: 700; line-height: 1.5;
  background: var(--grad);
  -webkit-background-clip: text; background-clip: text; color: transparent;
}

/* ---------- Footer ---------- */
.footer { border-top: 1px solid var(--border); padding: 34px 24px; }
.footer-inner {
  max-width: var(--container); margin: 0 auto;
  display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 8px;
  font-size: 13.5px; color: var(--text-dim);
}
.footer-inner a:hover { color: var(--accent-2); }

/* ---------- Download ---------- */
.download-grid {
  max-width: var(--container);
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
.download-card {
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 14px;
}
.download-platform { display: flex; flex-direction: column; align-items: center; gap: 12px; }
.download-platform h3 { font-size: 20px; margin: 0; }
.download-icon {
  width: 80px; height: 80px;
  border-radius: 18px;
  display: grid; place-items: center;
  background: #fff;
  padding: 14px;
  box-shadow: 0 8px 28px rgba(0, 0, 0, .4);
}
.download-icon img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  display: block;
}
.download-desc { font-size: 13.5px; color: var(--text-dim); min-height: 1.5em; }
.download-meta {
  width: 100%;
  margin: 0;
  padding: 14px 16px;
  border-radius: 12px;
  background: rgba(255, 255, 255, .03);
  border: 1px solid var(--border);
  display: grid;
  grid-template-columns: auto 1fr;
  row-gap: 8px;
  column-gap: 14px;
  text-align: left;
}
.download-meta dt {
  font-size: 12.5px;
  color: var(--text-dim);
  white-space: nowrap;
  padding-top: 1px;
}
.download-meta dd {
  margin: 0;
  font-size: 13px;
  color: var(--text);
  font-family: Consolas, "SFMono-Regular", Menlo, monospace;
  word-break: break-all;
  line-height: 1.4;
}
.download-card .btn { width: 100%; max-width: 240px; margin-top: auto; }
.download-card-disabled { opacity: .75; }
.download-card-disabled .download-icon {
  background: #e9ebf2;
  box-shadow: none;
  filter: grayscale(1);
}
.download-card-disabled .btn-ghost.disabled { cursor: not-allowed; opacity: .7; border-style: dashed; }

@media (max-width: 960px) {
  .download-grid { grid-template-columns: 1fr; }
  .download-card { padding: 32px 24px; }
}
.reveal { opacity: 0; transform: translateY(26px); transition: opacity .7s var(--ease), transform .7s var(--ease); }
.reveal.in { opacity: 1; transform: none; }

/* ---------- Responsive ---------- */
@media (max-width: 960px) {
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .tech-wrap { grid-template-columns: 1fr; }
  .tech-stack { position: static; }
}
@media (max-width: 720px) {
  .nav-links {
    position: fixed; top: 64px; left: 0; right: 0;
    flex-direction: column; gap: 0;
    background: rgba(13, 16, 24, .97);
    border-bottom: 1px solid var(--border);
    padding: 8px 24px 16px;
    transform: translateY(-8px); opacity: 0; pointer-events: none;
    transition: .3s var(--ease);
  }
  .nav-links.open { transform: none; opacity: 1; pointer-events: auto; }
  .nav-links a { padding: 12px 0; border-bottom: 1px solid rgba(36, 42, 63, .5); }
  .nav-links a:last-child { border-bottom: 0; }
  .nav-toggle { display: flex; }
  .hero { padding: 80px 24px 60px; }
  .hero-stats { gap: 36px; }
  .feature-grid { grid-template-columns: 1fr; }
  .about-inner { align-items: flex-start; }
  .intro-card { padding: 32px 24px; }
  .footer-inner { flex-direction: column; text-align: center; }
}