/* =========================================================================
   Kiilion Files · 科链文件  —  Official Site Design System (v2)
   UI Designer / 像素君  —  Design Tokens + Components
   ========================================================================= */

/* ----------------------------- Design Tokens ---------------------------- */
:root {
  /* Brand */
  --brand: #2f6bff;
  --brand-600: #1f4fd6;
  --brand-400: #5a93f6;
  --brand-300: #8ab4ff;
  --accent: #38e1ff;

  /* Gradient */
  --grad: linear-gradient(135deg, #4f8cff 0%, #38e1ff 100%);
  --grad-soft: linear-gradient(135deg, rgba(79,140,255,.18), rgba(56,225,255,.14));

  /* Semantic */
  --ok: #2dd4a7;
  --warn: #f7b955;
  --danger: #ff6b81;
  --info: #4f8cff;

  /* Typography */
  --font-sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, monospace;

  --fs-xs: .75rem;    /* 12 */
  --fs-sm: .875rem;   /* 14 */
  --fs-base: 1rem;    /* 16 */
  --fs-md: 1.0625rem; /* 17 */
  --fs-lg: 1.25rem;   /* 20 */
  --fs-xl: 1.5rem;    /* 24 */
  --fs-2xl: 2rem;     /* 32 */
  --fs-3xl: 2.75rem;  /* 44 */
  --fs-4xl: clamp(2.4rem, 6vw, 4rem);

  /* Spacing (4px base) */
  --s-1: 4px;  --s-2: 8px;  --s-3: 12px; --s-4: 16px;
  --s-5: 20px; --s-6: 24px; --s-8: 32px; --s-10: 40px;
  --s-12: 48px; --s-16: 64px; --s-20: 80px; --s-24: 96px;

  /* Radius */
  --r-sm: 8px;  --r-md: 12px; --r-lg: 18px; --r-xl: 26px; --r-full: 999px;

  /* Shadow */
  --sh-sm: 0 2px 8px rgba(0,0,0,.18);
  --sh-md: 0 12px 30px rgba(0,0,0,.28);
  --sh-lg: 0 24px 60px rgba(0,0,0,.40);
  --sh-glow: 0 0 0 1px rgba(79,140,255,.35), 0 18px 50px rgba(47,107,255,.28);

  /* Motion */
  --t-fast: .15s ease;
  --t: .28s cubic-bezier(.22,.61,.36,1);
  --t-slow: .5s cubic-bezier(.22,.61,.36,1);

  --maxw: 1180px;
  --nav-h: 68px;
}

/* ------------------------------- Themes ---------------------------------- */
:root,
[data-theme="dark"] {
  --bg: #080d1c;
  --bg-2: #0b1226;
  --bg-glow-1: rgba(47,107,255,.20);
  --bg-glow-2: rgba(56,225,255,.14);
  --surface: rgba(255,255,255,.045);
  --surface-2: rgba(255,255,255,.07);
  --surface-solid: #101a33;
  --border: rgba(255,255,255,.10);
  --border-strong: rgba(255,255,255,.18);
  --text: #eaf0ff;
  --text-2: #9fb0cf;
  --text-3: #6f80a3;
  --nav-bg: rgba(8,13,28,.72);
  --code-bg: rgba(255,255,255,.06);
  color-scheme: dark;
}

[data-theme="light"] {
  --bg: #f4f7fd;
  --bg-2: #eaf0fb;
  --bg-glow-1: rgba(47,107,255,.16);
  --bg-glow-2: rgba(56,225,255,.12);
  --surface: rgba(15,23,42,.035);
  --surface-2: rgba(15,23,42,.06);
  --surface-solid: #ffffff;
  --border: rgba(15,23,42,.10);
  --border-strong: rgba(15,23,42,.18);
  --text: #0e1830;
  --text-2: #51628a;
  --text-3: #8493b3;
  --nav-bg: rgba(244,247,253,.78);
  --code-bg: rgba(15,23,42,.05);
  color-scheme: light;
}

/* ------------------------------- Reset ----------------------------------- */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: var(--fs-base);
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
  background-attachment: fixed;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}
/* ambient glows */
body::before {
  content: "";
  position: fixed; inset: 0; z-index: -1; pointer-events: none;
  background:
    radial-gradient(60vw 60vw at 78% -8%, var(--bg-glow-1), transparent 60%),
    radial-gradient(48vw 48vw at 8% 6%, var(--bg-glow-2), transparent 55%),
    linear-gradient(180deg, var(--bg) 0%, var(--bg-2) 100%);
  background-attachment: fixed;
}
img, svg { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button { font-family: inherit; cursor: pointer; }
h1,h2,h3,h4 { margin: 0; line-height: 1.2; font-weight: 700; letter-spacing: -.01em; }
p { margin: 0; }
ul { margin: 0; padding: 0; list-style: none; }
:focus-visible { outline: 2px solid var(--brand-400); outline-offset: 3px; border-radius: 4px; }

/* ------------------------------ Layout ----------------------------------- */
.container { width: 100%; max-width: var(--maxw); margin: 0 auto; padding-inline: var(--s-5); }
.section { padding-block: var(--s-20); }
.section--tight { padding-block: var(--s-16); }
.divider-top { border-top: 1px solid var(--border); }

/* ------------------------------- Nav ------------------------------------- */
.nav {
  position: sticky; top: 0; z-index: 50;
  height: var(--nav-h);
  background: var(--nav-bg);
  backdrop-filter: saturate(160%) blur(14px);
  -webkit-backdrop-filter: saturate(160%) blur(14px);
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  height: 100%; max-width: var(--maxw); margin: 0 auto;
  padding-inline: var(--s-5);
  display: flex; align-items: center; gap: var(--s-5);
}
.brand { display: flex; align-items: center; gap: var(--s-3); font-weight: 800; }
.brand-logo { height: 38px; width: auto; border-radius: 10px; box-shadow: var(--sh-sm); }
.brand-name { font-size: 1.15rem; letter-spacing: .01em; }
.brand-name small { display: block; font-size: .62rem; font-weight: 600; color: var(--text-3); letter-spacing: .14em; text-transform: uppercase; }

.nav-links { display: flex; align-items: center; gap: var(--s-6); margin-left: auto; }
.nav-links a {
  font-size: var(--fs-sm); color: var(--text-2); font-weight: 500;
  position: relative; padding-block: 6px; transition: color var(--t-fast);
}
.nav-links a::after {
  content: ""; position: absolute; left: 0; bottom: 0; height: 2px; width: 0;
  background: var(--grad); transition: width var(--t);
}
.nav-links a:hover, .nav-links a.active { color: var(--text); }
.nav-links a.active::after, .nav-links a:hover::after { width: 100%; }

.nav-actions { display: flex; align-items: center; gap: var(--s-3); }
.nav-actions .btn { height: 40px; padding-block: 0; }
.icon-btn {
  width: 40px; height: 40px; display: grid; place-items: center;
  border: 1px solid var(--border); background: var(--surface);
  color: var(--text); border-radius: var(--r-md); transition: all var(--t-fast);
}
.icon-btn:hover { border-color: var(--brand-400); color: var(--brand-400); }
.lang-dropdown { position: relative; }
.lang-toggle { display: flex; align-items: center; min-width: 96px; justify-content: center; }
.caret { font-size: 10px; opacity: .7; transition: transform var(--t-fast); }
.lang-toggle[aria-expanded="true"] .caret { transform: rotate(180deg); }
.lang-menu {
  position: absolute; top: calc(100% + 10px); right: 0;
  min-width: 150px; padding: var(--s-2);
  background: var(--surface-solid); border: 1px solid var(--border);
  border-radius: var(--r-md); box-shadow: var(--sh-md); z-index: 60;
}
.lang-menu[hidden] { display: none; }
.lang-menu button {
  width: 100%; text-align: left; background: transparent; border: none;
  color: var(--text); padding: 9px 12px; border-radius: var(--r-sm);
  font-size: var(--fs-sm); display: flex; align-items: center; justify-content: space-between;
  transition: background var(--t-fast);
}
.lang-menu button:hover { background: var(--surface-2); }
.lang-menu button.active { color: var(--brand-400); font-weight: 700; }
.lang-menu button.active::after { content: "✓"; }

.nav-burger { display: none; }

/* ------------------------------ Buttons ---------------------------------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: var(--s-2);
  padding: 12px 22px; border-radius: var(--r-md); font-weight: 600; font-size: var(--fs-sm);
  border: 1px solid transparent; transition: transform var(--t-fast), background var(--t-fast), box-shadow var(--t-fast), border-color var(--t-fast);
  white-space: nowrap;
}
.btn:active { transform: translateY(1px); }
.btn-primary { background: var(--grad); color: #04122e; box-shadow: var(--sh-glow); }
.btn-primary:hover { filter: brightness(1.06); transform: translateY(-1px); }
.btn-ghost { background: var(--surface); border-color: var(--border); color: var(--text); }
.btn-ghost:hover { border-color: var(--brand-400); color: var(--brand-400); }
.btn-outline { background: transparent; border-color: var(--border-strong); color: var(--text); }
.btn-outline:hover { border-color: var(--brand-400); color: var(--brand-400); }
.btn-lg { padding: 15px 30px; font-size: var(--fs-md); }
.btn-block { width: 100%; }

/* --------------------------- Section header ------------------------------ */
.eyebrow {
  display: inline-flex; align-items: center; gap: var(--s-2);
  font-size: var(--fs-xs); font-weight: 700; letter-spacing: .14em; text-transform: uppercase;
  color: var(--brand-400); margin-bottom: var(--s-4);
  padding: 6px 12px; border: 1px solid var(--border); border-radius: var(--r-full);
  background: var(--surface);
}
.eyebrow .dot { width: 6px; height: 6px; border-radius: 50%; background: var(--grad); }
.sec-title { font-size: var(--fs-3xl); text-align: center; max-width: 18ch; margin: 0 auto var(--s-4); }
.sec-sub { text-align: center; color: var(--text-2); max-width: 60ch; margin: 0 auto var(--s-12); font-size: var(--fs-md); }

/* ------------------------------- Hero ------------------------------------ */
.hero { position: relative; padding-block: clamp(48px, 9vw, 110px) var(--s-16); }
.hero-grid { display: grid; grid-template-columns: 1.05fr .95fr; gap: var(--s-12); align-items: center; }
.hero h1 { font-size: var(--fs-4xl); font-weight: 800; }
.hero h1 .grad {
  background: var(--grad); -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent; color: transparent;
}
.hero-lead { color: var(--text-2); font-size: var(--fs-lg); margin-top: var(--s-5); max-width: 46ch; }
.hero-cta { display: flex; gap: var(--s-3); margin-top: var(--s-8); flex-wrap: wrap; }

/* Hero device mockup */
.phone {
  position: relative; width: min(300px, 78%); margin-inline: auto; aspect-ratio: 9/19;
  border-radius: 38px; padding: 10px;
  background: linear-gradient(160deg, #1b2540, #0a1124);
  border: 1px solid var(--border-strong);
  box-shadow: var(--sh-lg), inset 0 0 0 2px rgba(255,255,255,.04);
}
.phone::before { /* notch（截图自带状态栏，隐藏设备刘海以免重叠） */
  display: none;
}
.phone-screen {
  height: 100%; border-radius: 30px; overflow: hidden; position: relative;
  background: #0a1020; display: block;
}
.ph-shot { display: block; width: 100%; height: 100%; object-fit: cover; }



/* --------------------------- Feature cards ------------------------------- */
.cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--s-5); }
.card {
  position: relative; padding: var(--s-6); border-radius: var(--r-lg);
  background: var(--surface); border: 1px solid var(--border);
  transition: transform var(--t), border-color var(--t), background var(--t), box-shadow var(--t);
  overflow: hidden;
}
.card::after { /* hover sheen */
  content: ""; position: absolute; inset: 0; border-radius: inherit;
  background: radial-gradient(120% 80% at 0% 0%, var(--grad-soft), transparent 55%);
  opacity: 0; transition: opacity var(--t);
}
.card:hover { transform: translateY(-4px); border-color: var(--border-strong); box-shadow: var(--sh-md); }
.card:hover::after { opacity: 1; }
.card .c-ico {
  width: 52px; height: 52px; border-radius: 14px; display: grid; place-items: center;
  background: var(--grad-soft); color: var(--brand-400); margin-bottom: var(--s-4);
  border: 1px solid var(--border); position: relative; z-index: 1;
}
.card h3 { font-size: var(--fs-lg); margin-bottom: var(--s-2); position: relative; z-index: 1; }
.card p { color: var(--text-2); font-size: var(--fs-sm); position: relative; z-index: 1; }
.card .tags { display: flex; flex-wrap: wrap; gap: 6px; margin-top: var(--s-4); position: relative; z-index: 1; }
.tag {
  font-size: var(--fs-xs); color: var(--text-2); padding: 4px 9px; border-radius: var(--r-full);
  border: 1px solid var(--border); background: var(--surface-2);
}
.tag.ok { color: var(--ok); border-color: rgba(45,212,167,.35); }

/* ----------------------- Deep-dive split sections ----------------------- */
.split { display: grid; grid-template-columns: 1fr 1fr; gap: var(--s-12); align-items: center; }
.split.reverse .visual { order: -1; }
.split h2 { font-size: var(--fs-2xl); margin-bottom: var(--s-4); }
.split p { color: var(--text-2); font-size: var(--fs-md); margin-bottom: var(--s-5); }
.feat-list { display: grid; gap: var(--s-3); }
.feat-list li { display: flex; gap: var(--s-3); align-items: flex-start; color: var(--text); font-size: var(--fs-sm); }
.feat-list .ck { flex: none; width: 22px; height: 22px; border-radius: 50%; display: grid; place-items: center; background: var(--grad-soft); color: var(--accent); font-size: .7rem; margin-top: 2px; }

/* visual panel */
.panel {
  border-radius: var(--r-xl); padding: var(--s-6);
  background: linear-gradient(170deg, var(--surface-2), var(--surface));
  border: 1px solid var(--border); box-shadow: var(--sh-md); position: relative; overflow: hidden;
}
.panel-grid { display: grid; grid-template-columns: repeat(2,1fr); gap: var(--s-3); }
.panel-tile { padding: var(--s-4); border-radius: var(--r-md); background: var(--surface-solid); border: 1px solid var(--border); }
.panel-tile .t-ico { color: var(--brand-400); margin-bottom: var(--s-2); }
.panel-tile b { display: block; font-size: var(--fs-sm); }
.panel-tile span { font-size: var(--fs-xs); color: var(--text-3); }
.panel-cap { margin: 0 0 var(--s-4); font-size: var(--fs-xs); color: var(--text-3); letter-spacing: .04em; text-transform: uppercase; }
/* encryption flow (icon-free timeline) */
.flow { position: relative; }
.flow::before {
  content: ""; position: absolute; left: 16px; top: 29px; bottom: 29px;
  width: 2px; background: var(--border); z-index: 0;
}
.flow-step { position: relative; display: flex; align-items: center; gap: var(--s-4); padding: var(--s-3) 0; }
.flow-badge {
  flex: 0 0 auto; width: 34px; height: 34px; border-radius: 50%;
  display: grid; place-items: center; font-weight: 700; font-size: var(--fs-sm);
  color: var(--brand-400); background: var(--surface-solid);
  border: 1px solid var(--brand-400); position: relative; z-index: 1;
}
.flow-body b { display: block; font-size: var(--fs-sm); color: var(--text-1); }
.flow-body span { font-size: var(--fs-xs); color: var(--text-3); }
.flow-step.is-end .flow-badge { color: #05070f; background: var(--brand-400); border-color: var(--brand-400); }

/* code/terminal mock */
.term { border-radius: var(--r-md); background: #05070f; border: 1px solid var(--border); overflow: hidden; }
.term-bar { display: flex; gap: 6px; padding: 10px 12px; border-bottom: 1px solid var(--border); }
.term-bar i { width: 10px; height: 10px; border-radius: 50%; display: block; }
.term pre { margin: 0; padding: var(--s-4); font-family: var(--font-mono); font-size: var(--fs-xs); color: #cfe0ff; overflow-x: auto; line-height: 1.7; }
.term pre .c { color: var(--accent); } .term pre .g { color: #6ee7a8; } .term pre .m { color: var(--text-3); }
/* terminal typewriter (vault block): JS types char-by-char with a following cursor */
.term pre.t-anim { height: 14.5em; overflow-y: auto; scrollbar-width: none; -ms-overflow-style: none; }
.term pre.t-anim::-webkit-scrollbar { width: 0; height: 0; }
.term pre.t-anim .tline { display: block; white-space: pre; }
.term pre .cur { display: inline-block; color: var(--accent); font-weight: 700; animation: curBlink 1.05s steps(1) infinite; }
@keyframes curBlink { 0%, 50% { opacity: 1; } 50.01%, 100% { opacity: 0; } }

/* device connection card (phone cloud) */
.conncard {
  border-radius: var(--r-xl); padding: var(--s-6);
  background: linear-gradient(170deg, var(--surface-2), var(--surface));
  border: 1px solid var(--border); box-shadow: var(--sh-md);
  position: relative; overflow: hidden;
}
.conn-head { display: flex; align-items: center; gap: var(--s-3); margin-bottom: var(--s-5); }
.conn-dot {
  width: 9px; height: 9px; border-radius: 50%; background: var(--ok);
  box-shadow: 0 0 0 4px rgba(45,212,167,.18);
  animation: connPulse 1.8s ease-in-out infinite;
}
@keyframes connPulse { 0%,100% { box-shadow: 0 0 0 3px rgba(45,212,167,.22); } 50% { box-shadow: 0 0 0 7px rgba(45,212,167,.06); } }
.conn-title { font-weight: 600; font-size: var(--fs-sm); color: var(--text); }
.conn-ip { margin-left: auto; font-family: var(--font-mono); font-size: var(--fs-xs); color: var(--text-3); }
.conn-file { display: flex; align-items: baseline; justify-content: space-between; margin-bottom: var(--s-3); }
.conn-fname { font-family: var(--font-mono); font-size: var(--fs-sm); color: var(--accent); }
.conn-pct { font-size: var(--fs-sm); font-weight: 700; color: var(--text); }
.conn-bar { height: 8px; border-radius: var(--r-full); background: var(--surface-2); overflow: hidden; }
.conn-bar i { display: block; height: 100%; width: 68%; border-radius: inherit; background: var(--grad); position: relative; overflow: hidden; }
.conn-bar i::after {
  content: ""; position: absolute; inset: 0;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,.55), transparent);
  transform: translateX(-100%); animation: connShimmer 1.8s infinite;
}
@keyframes connShimmer { 100% { transform: translateX(100%); } }
.conn-meta { display: flex; justify-content: space-between; align-items: center; margin-top: var(--s-3); font-size: var(--fs-xs); color: var(--text-3); font-family: var(--font-mono); }
.conn-xfer { color: var(--text-2); }
.conn-speed { color: var(--ok); font-weight: 600; }



/* ---------------------------- Roadmap timeline --------------------------- */
.roadmap { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--s-5); position: relative; }
.road {
  padding: var(--s-6); border-radius: var(--r-lg); border: 1px solid var(--border);
  background: var(--surface); position: relative;
}
.road .stage { font-size: var(--fs-xs); font-weight: 700; letter-spacing: .12em; text-transform: uppercase; color: var(--brand-400); }
.road h3 { font-size: var(--fs-xl); margin: var(--s-2) 0; }
.road p { color: var(--text-2); font-size: var(--fs-sm); margin-bottom: var(--s-4); }
.road .status { display: inline-flex; align-items: center; gap: 6px; font-size: var(--fs-xs); font-weight: 600; padding: 5px 11px; border-radius: var(--r-full); }
.road .status.live { color: var(--ok); background: rgba(45,212,167,.12); border: 1px solid rgba(45,212,167,.3); }
.road .status.soon { color: var(--warn); background: rgba(247,185,85,.12); border: 1px solid rgba(247,185,85,.3); }
.road .status.plan { color: var(--text-3); background: var(--surface-2); border: 1px solid var(--border); }
.road.featured { border-color: var(--brand-400); box-shadow: var(--sh-glow); }



/* ------------------------------- Donate ---------------------------------- */
.donate-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: var(--s-5); align-items: stretch; }
.donate {
  padding: var(--s-6); border-radius: var(--r-lg); border: 1px solid var(--border);
  background: var(--surface); text-align: center; transition: transform var(--t), border-color var(--t), background var(--t);
  display: flex; flex-direction: column; align-items: center; cursor: pointer;
  font: inherit; color: inherit; appearance: none; width: 100%;
}
.donate:hover { transform: translateY(-4px); border-color: var(--border-strong); background: var(--surface-2); }
.donate:focus-visible { outline: 2px solid var(--brand-400); outline-offset: 2px; }
.donate .d-ico { width: 56px; height: 56px; margin: 0 auto var(--s-3); border-radius: 16px; display: grid; place-items: center; background: var(--grad-soft); }
.donate .d-ico svg { width: 40px; height: 40px; display: block; }
.donate h3 { font-size: var(--fs-lg); margin: 0; }
.donate .d-sub { display: block; margin-top: 4px; font-size: var(--fs-xs); font-weight: 500; color: var(--text-2); }
.donate .d-desc { color: var(--text-2); font-size: var(--fs-xs); margin-top: var(--s-2); }

/* Donate modal */
.modal { position: fixed; inset: 0; z-index: 1000; display: grid; place-items: center; padding: var(--s-5); }
.modal[hidden] { display: none; }
.modal-backdrop { position: absolute; inset: 0; background: rgba(0,0,0,.78); backdrop-filter: blur(4px); }
.modal-card { position: relative; width: min(520px, 100%); max-height: 92vh; overflow: auto; border: 1px solid var(--border-strong); border-radius: var(--r-xl); padding: var(--s-10) var(--s-8) var(--s-8); box-shadow: var(--shadow, 0 28px 70px rgba(0,0,0,.45)); background: radial-gradient(130% 100% at 50% -10%, var(--grad-soft), transparent 55%), var(--surface-solid); }
.modal-card--wide { width: min(760px, 100%); }
.modal-close { position: absolute; top: 12px; right: 12px; width: 34px; height: 34px; border-radius: 50%; border: 1px solid var(--border); background: var(--surface-2); color: var(--text-2); font-size: 20px; line-height: 1; cursor: pointer; transition: var(--t); }
.modal-close:hover { color: var(--text); border-color: var(--border-strong); }
.dm-head { text-align: center; }
.dm-ico { width: 64px; height: 64px; margin: 0 auto var(--s-3); border-radius: 18px; display: grid; place-items: center; background: var(--grad-soft); }
.dm-ico svg { width: 46px; height: 46px; display: block; }
.dm-head h3 { font-size: var(--fs-xl); }
.dm-desc { color: var(--text-2); font-size: var(--fs-sm); margin-top: var(--s-2); line-height: 1.6; }
.dm-qr { display: block; width: 100%; max-width: 100%; height: auto; margin: var(--s-5) auto 0; border-radius: 14px; }
.dm-addr-row { display: flex; gap: var(--s-2); align-items: stretch; margin-top: var(--s-5); }
.dm-addr { flex: 1; font-family: var(--font-mono); font-size: 12px; line-height: 1.5; background: var(--surface-2); border: 1px solid var(--border); border-radius: 10px; padding: 10px 12px; color: var(--text); word-break: break-all; text-align: left; }
.dm-copy { flex: 0 0 auto; font-size: var(--fs-sm); color: var(--brand-400); background: transparent; border: 1px solid var(--border-strong); border-radius: 10px; padding: 0 16px; cursor: pointer; transition: var(--t); }
.dm-copy:hover { border-color: var(--brand-400); }
.dm-link { display: inline-block; margin-top: var(--s-5); font-size: var(--fs-sm); color: #fff; background: var(--brand-400); text-decoration: none; padding: 10px 20px; border-radius: 10px; transition: var(--t); }
.dm-link:hover { opacity: .9; }
.dm-qr { cursor: zoom-in; }
.lightbox { position: fixed; inset: 0; z-index: 1100; display: grid; place-items: center; padding: var(--s-6); }
.lightbox[hidden] { display: none; }
.lightbox-backdrop { position: absolute; inset: 0; background: rgba(0,0,0,.82); backdrop-filter: blur(4px); }
.lightbox-card { position: relative; display: flex; flex-direction: column; align-items: center; gap: var(--s-4); max-width: 92vw; max-height: 92vh; }
.lightbox-img { display: block; max-width: 92vw; max-height: 78vh; width: auto; height: auto; border-radius: 14px; background: var(--surface-solid); box-shadow: 0 20px 60px rgba(0,0,0,.5); }
.lightbox-close { position: absolute; top: -14px; right: -14px; width: 38px; height: 38px; border-radius: 50%; border: 1px solid var(--border); background: var(--surface-2); color: var(--text-2); font-size: 22px; line-height: 1; cursor: pointer; transition: var(--t); }
.lightbox-close:hover { color: var(--text); border-color: var(--border-strong); }
.lightbox-actions { display: flex; gap: var(--s-3); }
.lightbox-dl { display: inline-block; font-size: var(--fs-sm); color: #fff; background: var(--brand-400); text-decoration: none; padding: 10px 22px; border-radius: 10px; transition: var(--t); }
.lightbox-dl:hover { opacity: .9; }
.dm-link--top { display: block; width: fit-content; margin: 0 auto var(--s-5); }
.dm-qr-grid { display: grid; grid-template-columns: 1fr 1fr; gap: var(--s-3) var(--s-4); align-items: start; margin-top: var(--s-6); }
.dm-qr-grid .dm-qr-label { font-weight: 700; font-size: var(--fs-sm); color: var(--text); text-align: center; }
.dm-qr-grid .dm-qr { margin: 0; }

/* feedback modal */
.fb-title { font-size: var(--fs-xl); margin-bottom: var(--s-2); }
.fb-intro { color: var(--text-2); font-size: var(--fs-sm); line-height: 1.6; margin-bottom: var(--s-5); }
.fb-list { list-style: none; margin: 0; padding: 0; display: grid; gap: var(--s-3); }
.fb-item { display: flex; align-items: center; gap: var(--s-3); padding: var(--s-4); border: 1px solid var(--border); border-radius: var(--r-md); background: var(--surface-2); text-decoration: none; color: var(--text); transition: var(--t); }
.fb-item:hover { border-color: var(--brand-400); background: var(--surface-solid); }
.fb-ico { flex: 0 0 auto; width: 36px; height: 36px; border-radius: 10px; display: grid; place-items: center; background: var(--brand-400); color: #05070f; font-size: 15px; font-weight: 700; }
.fb-text { display: flex; flex-direction: column; gap: 2px; }
.fb-text b { font-size: var(--fs-sm); }
.fb-text span { font-size: var(--fs-xs); color: var(--text-3); }

/* ------------------------------- Footer ---------------------------------- */
.footer { border-top: 1px solid var(--border); padding-block: var(--s-12) var(--s-8); }
.footer-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr 1fr; gap: var(--s-8); }
.footer .f-brand p { color: var(--text-2); font-size: var(--fs-sm); margin-top: var(--s-3); max-width: 34ch; }
.footer h4 { font-size: var(--fs-sm); color: var(--text); margin-bottom: var(--s-3); letter-spacing: .04em; }
.footer ul li { margin-bottom: var(--s-2); }
.footer ul a { color: var(--text-2); font-size: var(--fs-sm); transition: color var(--t-fast); }
.footer ul a:hover { color: var(--brand-400); }
.footer-bottom { display: flex; flex-wrap: wrap; gap: var(--s-3); justify-content: space-between; align-items: center; margin-top: var(--s-10); padding-top: var(--s-5); border-top: 1px solid var(--border); color: var(--text-3); font-size: var(--fs-xs); }

/* --------------------------- Scroll reveal ------------------------------- */
.reveal { opacity: 0; transform: translateY(24px); transition: opacity var(--t-slow), transform var(--t-slow); }
.reveal.in { opacity: 1; transform: none; }
.reveal.d1 { transition-delay: .08s; } .reveal.d2 { transition-delay: .16s; }
.reveal.d3 { transition-delay: .24s; } .reveal.d4 { transition-delay: .32s; }
@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; scroll-behavior: auto !important; }
  .reveal { opacity: 1; transform: none; transition: none; }
}

/* ----------------------------- Responsive -------------------------------- */
@media (max-width: 960px) {
  .hero-grid, .split { grid-template-columns: 1fr; }
  .split.reverse .visual { order: 0; }
  .cards { grid-template-columns: repeat(2, 1fr); }
  .donate-grid { grid-template-columns: repeat(2, 1fr); }
  .roadmap { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .hero-visual { order: -1; }
}
@media (max-width: 680px) {
  :root { --nav-h: 60px; }
  .nav-links { display: none; }
  .nav-links.open {
    display: flex; flex-direction: column; gap: var(--s-4);
    position: absolute; top: var(--nav-h); left: 0; right: 0;
    background: var(--surface-solid); border-bottom: 1px solid var(--border);
    padding: var(--s-5); margin: 0;
  }
  .nav-burger { display: grid; }
  .nav-actions .btn-primary { display: none; }
  .cards, .donate-grid, .footer-grid { grid-template-columns: 1fr; }
  .panel-grid { grid-template-columns: 1fr; }
  .sec-title { font-size: var(--fs-2xl); }
  .section { padding-block: var(--s-16); }
}

/* 极小屏（手机竖屏）补充优化 */
@media (max-width: 480px) {
  .container { padding-inline: var(--s-4); }
  .modal { padding: var(--s-3); }
  .modal-card { padding: var(--s-8) var(--s-5) var(--s-6); border-radius: var(--r-lg); }

  .dm-qr-grid { grid-template-columns: 1fr; gap: var(--s-5); }
  .dm-addr-row { flex-direction: column; }
  .dm-copy { width: 100%; }
  .hero-cta { flex-direction: column; align-items: stretch; }
  .hero-cta .btn { width: 100%; justify-content: center; }
  .footer-bottom { flex-direction: column; align-items: flex-start; }
}