/* ============================================================
   CLEARQ · Liquid Glass
   ============================================================ */

:root {
  --bg: #05060a;
  --ink: #eef2f8;
  --ink-dim: rgba(238, 242, 248, .70);
  --ink-faint: rgba(238, 242, 248, .40);
  --line: rgba(255, 255, 255, .10);

  --cyan: #7ec8ff;
  --violet: #b79bff;
  --mint: #7ff0d0;

  --r-lg: 28px;
  --r-md: 22px;
  --ease: cubic-bezier(.22, .61, .36, 1);
  --max: 1120px;
}

*, *::before, *::after { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background: var(--bg);
  color: var(--ink);
  font-family: "SF Pro Display", -apple-system, BlinkMacSystemFont, "Segoe UI",
    "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "HarmonyOS Sans SC", sans-serif;
  font-size: 16px;
  line-height: 1.6;
  letter-spacing: .002em;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

a { color: inherit; text-decoration: none; }
h1, h2, h3, p, ul { margin: 0; }
ul { padding: 0; list-style: none; }
svg { display: block; }

::selection { background: rgba(126, 200, 255, .28); color: #fff; }

:focus-visible {
  outline: 2px solid rgba(160, 215, 255, .8);
  outline-offset: 3px;
  border-radius: 10px;
}

/* ---------------- 背景 ---------------- */

.bg {
  position: fixed;
  inset: 0;
  z-index: -2;
  overflow: hidden;
  background:
    radial-gradient(120% 80% at 50% -12%, #0c1526 0%, #060810 46%, #04050a 100%);
}

.blob {
  position: absolute;
  display: block;
  border-radius: 50%;
  filter: blur(96px);
  opacity: .58;
  will-change: transform;
}

.blob-a {
  width: 46vw; height: 46vw; min-width: 380px; min-height: 380px;
  top: -14vw; left: -6vw;
  background: radial-gradient(circle at 40% 40%, rgba(62, 132, 232, .62), rgba(40, 90, 200, 0) 70%);
  animation: drift-a 26s var(--ease) infinite alternate;
}

.blob-b {
  opacity: .48;
  width: 42vw; height: 42vw; min-width: 340px; min-height: 340px;
  top: -10vw; right: -18vw;
  background: radial-gradient(circle at 50% 50%, rgba(126, 112, 220, .28), rgba(90, 70, 200, 0) 70%);
  animation: drift-b 32s var(--ease) infinite alternate;
}

.blob-c {
  width: 50vw; height: 40vw; min-width: 380px; min-height: 320px;
  bottom: -22vw; left: 30%;
  background: radial-gradient(circle at 50% 50%, rgba(45, 200, 178, .26), rgba(20, 120, 140, 0) 70%);
  animation: drift-c 38s var(--ease) infinite alternate;
}

.blob-d {
  width: 44vw; height: 44vw; min-width: 360px; min-height: 360px;
  top: 30%; left: 36%;
  background: radial-gradient(circle at 50% 50%, rgba(88, 128, 226, .24), rgba(50, 70, 180, 0) 70%);
  animation: drift-d 44s var(--ease) infinite alternate;
}

@keyframes drift-d {
  from { transform: translate3d(0, 0, 0) scale(.95); }
  to   { transform: translate3d(3vw, -6vh, 0) scale(1.08); }
}

@keyframes drift-a {
  from { transform: translate3d(0, 0, 0) scale(1); }
  to   { transform: translate3d(6vw, 5vh, 0) scale(1.12); }
}
@keyframes drift-b {
  from { transform: translate3d(0, 0, 0) scale(1.05); }
  to   { transform: translate3d(-5vw, 7vh, 0) scale(.94); }
}
@keyframes drift-c {
  from { transform: translate3d(0, 0, 0) scale(1); }
  to   { transform: translate3d(-4vw, -4vh, 0) scale(1.1); }
}

/* 细网格 */
.grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, rgba(255, 255, 255, .07) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(255, 255, 255, .07) 1px, transparent 1px);
  background-size: 76px 76px;
  -webkit-mask-image: radial-gradient(120% 90% at 50% 0%, #000 0%, rgba(0, 0, 0, .55) 40%, transparent 78%);
  mask-image: radial-gradient(120% 90% at 50% 0%, #000 0%, rgba(0, 0, 0, .55) 40%, transparent 78%);
}

/* 颗粒 */
.noise {
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  opacity: .035;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.8' numOctaves='3'/%3E%3C/filter%3E%3Crect width='160' height='160' filter='url(%23n)'/%3E%3C/svg%3E");
}

/* ---------------- 玻璃基类 ---------------- */

.glass {
  position: relative;
  isolation: isolate;
  border-radius: var(--r-md);
  background:
    linear-gradient(152deg, rgba(255, 255, 255, .135) 0%, rgba(255, 255, 255, .045) 44%, rgba(255, 255, 255, .075) 100%);
  border: 1px solid rgba(255, 255, 255, .11);
  -webkit-backdrop-filter: blur(28px) saturate(165%);
  backdrop-filter: blur(28px) saturate(165%);
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, .26),
    inset 0 -1px 0 rgba(255, 255, 255, .05),
    0 26px 60px -28px rgba(0, 0, 0, .9),
    0 2px 14px -6px rgba(120, 175, 255, .10);
}

/* 渐变描边：模拟玻璃边缘的折射高光 */
.glass::before {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  padding: 1px;
  background: linear-gradient(145deg,
    rgba(214, 238, 255, .78) 0%,
    rgba(255, 255, 255, .13) 23%,
    rgba(255, 255, 255, .015) 50%,
    rgba(198, 182, 255, .34) 78%,
    rgba(255, 255, 255, .07) 100%);
  -webkit-mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
  -webkit-mask-composite: xor;
  mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
  mask-composite: exclude;
  pointer-events: none;
  z-index: 2;
}

/* 玻璃顶部的柔和反光 */
.glass::after {
  content: "";
  position: absolute;
  top: 0;
  left: 6%;
  right: 6%;
  height: 52%;
  z-index: 0;
  border-radius: inherit;
  background: radial-gradient(64% 100% at 50% 0%, rgba(255, 255, 255, .14), rgba(255, 255, 255, 0) 72%);
  -webkit-mask-image: linear-gradient(180deg, #000 0%, rgba(0, 0, 0, .6) 55%, transparent 100%);
  mask-image: linear-gradient(180deg, #000 0%, rgba(0, 0, 0, .6) 55%, transparent 100%);
  pointer-events: none;
}

/* ---------------- 导航 ---------------- */

.site-head {
  position: sticky;
  top: 0;
  z-index: 60;
  padding: 18px 24px 0;
}

.site-head::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background: linear-gradient(180deg, rgba(5, 6, 10, .96) 0%, rgba(5, 6, 10, .72) 62%, rgba(5, 6, 10, 0) 100%);
}

.nav {
  background:
    linear-gradient(152deg, rgba(255, 255, 255, .14) 0%, rgba(255, 255, 255, .04) 46%, rgba(255, 255, 255, .08) 100%),
    rgba(9, 12, 20, .58);
  max-width: var(--max);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 9px 10px 9px 20px;
  border-radius: 999px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}

.brand-mark { flex-shrink: 0; }

.brand-name {
  font-size: 15px;
  font-weight: 600;
  letter-spacing: .14em;
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
}

.brand-name em {
  font-style: normal;
  font-size: 13px;
  font-weight: 500;
  letter-spacing: .18em;
  color: var(--ink-faint);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 4px;
  margin-right: auto;
  margin-left: 12px;
}

.nav-links a {
  display: inline-block;
  padding: 7px 13px;
  font-size: 14px;
  color: var(--ink-dim);
  border-radius: 999px;
  transition: color .25s var(--ease), background-color .25s var(--ease);
}

.nav-links a:hover {
  color: var(--ink);
  background: rgba(255, 255, 255, .06);
}

/* ---------------- 按钮 ---------------- */

.btn {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-size: 14.5px;
  font-weight: 500;
  border-radius: 999px;
  padding: 13px 24px;
  cursor: pointer;
  white-space: nowrap;
  transition: transform .3s var(--ease), box-shadow .3s var(--ease),
              background-color .3s var(--ease), border-color .3s var(--ease);
}

.arr {
  display: inline-block;
  font-size: 13px;
  transition: transform .3s var(--ease);
}

.btn:hover .arr { transform: translateX(3px); }

.btn-primary {
  color: #08101c;
  background: linear-gradient(180deg, #ffffff 0%, #dfeaf5 100%);
  border: 1px solid rgba(255, 255, 255, .9);
  box-shadow:
    0 1px 0 rgba(255, 255, 255, .9) inset,
    0 12px 34px -14px rgba(170, 215, 255, .8),
    0 2px 10px rgba(0, 0, 0, .35);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow:
    0 1px 0 rgba(255, 255, 255, .9) inset,
    0 18px 44px -14px rgba(170, 215, 255, .95),
    0 4px 14px rgba(0, 0, 0, .4);
}

.btn-ghost {
  color: var(--ink);
  background: rgba(255, 255, 255, .05);
  border: 1px solid rgba(255, 255, 255, .14);
  -webkit-backdrop-filter: blur(16px);
  backdrop-filter: blur(16px);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, .14);
}

.btn-ghost:hover {
  transform: translateY(-2px);
  background: rgba(255, 255, 255, .09);
  border-color: rgba(255, 255, 255, .26);
}

.btn-mini {
  padding: 9px 18px;
  font-size: 13.5px;
  color: var(--ink);
  background: rgba(255, 255, 255, .08);
  border: 1px solid rgba(255, 255, 255, .16);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, .18);
}

.btn-mini:hover {
  background: rgba(255, 255, 255, .15);
  transform: translateY(-1px);
}

main { flex: 1 0 auto; }

/* ---------------- Hero ---------------- */

.hero > * { min-width: 0; }

.grid-subjects > *,
.grid-features > * { min-width: 0; }

.hero {
  max-width: var(--max);
  margin: 0 auto;
  padding: 60px 24px 32px;
  display: grid;
  grid-template-columns: 1.04fr .96fr;
  align-items: center;
  gap: 60px;
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 6px 14px 6px 10px;
  font-size: 12.5px;
  letter-spacing: .04em;
  color: rgba(238, 242, 248, .74);
  background: rgba(255, 255, 255, .045);
  border: 1px solid rgba(255, 255, 255, .1);
  border-radius: 999px;
  -webkit-backdrop-filter: blur(14px);
  backdrop-filter: blur(14px);
}

.dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--mint);
  box-shadow: 0 0 0 4px rgba(127, 240, 208, .12), 0 0 12px rgba(127, 240, 208, .8);
  animation: pulse 2.6s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: .55; transform: scale(.86); }
}

h1 {
  margin: 22px 0 0;
  font-size: clamp(2.5rem, 5.4vw, 4.1rem);
  line-height: 1.14;
  font-weight: 600;
  letter-spacing: -.015em;
}

.grad {
  background: linear-gradient(102deg, #ffffff 2%, #a8d6ff 38%, #c3aaff 70%, #93f2dc 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.lede {
  margin-top: 18px;
  max-width: 30em;
  font-size: 16px;
  line-height: 1.78;
  color: var(--ink-dim);
}

.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 30px;
}

.hero-meta {
  display: flex;
  align-items: center;
  gap: 30px;
  margin-top: 36px;
  padding-top: 22px;
  border-top: 1px solid rgba(255, 255, 255, .07);
  max-width: 430px;
}

.hero-meta > div {
  display: flex;
  flex-direction: column;
  gap: 3px;
}

.hero-meta strong {
  font-size: 20px;
  font-weight: 500;
  letter-spacing: .02em;
  font-variant-numeric: tabular-nums;
  color: rgba(238, 242, 248, .92);
}

.hero-meta span {
  font-size: 12px;
  letter-spacing: .05em;
  color: var(--ink-faint);
}

/* ---------------- 预览卡 ---------------- */

.hero-visual {
  position: relative;
  display: flex;
  justify-content: flex-end;
}

.hero-visual::before {
  content: "";
  position: absolute;
  inset: 6% 0 -8% 4%;
  z-index: -1;
  background:
    radial-gradient(58% 58% at 62% 38%, rgba(86, 150, 255, .38), transparent 72%),
    radial-gradient(50% 50% at 30% 72%, rgba(140, 112, 232, .22), transparent 74%);
  filter: blur(46px);
}

.preview {
  width: 100%;
  max-width: min(408px, 100%);
  padding: 22px;
  border-radius: var(--r-lg);
  transform: rotate(-1deg);
  overflow: visible;
  animation: float 9s ease-in-out infinite alternate;
}

@keyframes float {
  from { translate: 0 0; }
  to   { translate: 0 -10px; }
}

.preview-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 12px;
  letter-spacing: .04em;
}

.preview-label { color: rgba(238, 242, 248, .68); }

.preview-count {
  color: var(--ink-faint);
  font-variant-numeric: tabular-nums;
}

.bar {
  height: 3px;
  margin: 12px 0 22px;
  border-radius: 999px;
  background: rgba(255, 255, 255, .08);
  overflow: hidden;
}

.bar i {
  display: block;
  width: 30%;
  height: 100%;
  border-radius: 999px;
  background: linear-gradient(90deg, #7ec8ff, #b79bff);
  box-shadow: 0 0 12px rgba(140, 190, 255, .7);
}

.q {
  font-size: 15.5px;
  line-height: 1.66;
  color: rgba(238, 242, 248, .9);
  font-family: ui-serif, Georgia, "Songti SC", serif;
}

.q b { color: #bfe3ff; font-weight: 600; }

.opts {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-top: 18px;
}

.opt {
  display: flex;
  align-items: center;
  gap: 11px;
  padding: 10px 13px;
  font-size: 14px;
  color: rgba(238, 242, 248, .84);
  border-radius: 13px;
  border: 1px solid rgba(255, 255, 255, .07);
  background: rgba(255, 255, 255, .035);
}

.opt-key {
  display: grid;
  place-items: center;
  width: 21px;
  height: 21px;
  flex-shrink: 0;
  font-size: 11px;
  border-radius: 50%;
  color: var(--ink-faint);
  border: 1px solid rgba(255, 255, 255, .14);
}

.opt em {
  margin-left: auto;
  font-style: normal;
  font-size: 11.5px;
  color: rgba(238, 242, 248, .5);
}

.opt.is-right {
  border-color: rgba(127, 240, 208, .3);
  background: linear-gradient(90deg, rgba(127, 240, 208, .13), rgba(127, 240, 208, .04));
  color: #e7fff8;
}

.opt.is-right .opt-key {
  color: #06120f;
  border-color: transparent;
  background: var(--mint);
}

.opt-check {
  font-style: normal;
  font-size: 11px;
  color: var(--mint);
}

.preview-foot {
  display: flex;
  align-items: center;
  gap: 18px;
  margin-top: 20px;
  padding-top: 14px;
  border-top: 1px solid rgba(255, 255, 255, .07);
  font-size: 11.5px;
  letter-spacing: .04em;
  color: rgba(238, 242, 248, .5);
}

.streak { display: inline-flex; align-items: center; gap: 7px; }

.streak i {
  width: 5px; height: 5px;
  border-radius: 50%;
  background: #ffcf8a;
  box-shadow: 0 0 10px rgba(255, 207, 138, .9);
}

.acc { margin-left: auto; font-variant-numeric: tabular-nums; }

.float-chip {
  position: absolute;
  right: 0;
  bottom: -34px;
  padding: 11px 15px;
  border-radius: 16px;
  font-size: 12px;
  letter-spacing: .03em;
  color: rgba(238, 242, 248, .88);
  display: flex;
  align-items: center;
  gap: 10px;
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, .2),
    0 18px 40px -18px rgba(0, 0, 0, .95);
}

.float-chip span {
  font-size: 11px;
  padding: 2px 7px;
  border-radius: 999px;
  color: #06120f;
  background: var(--mint);
}

/* ---------------- 分区通用 ---------------- */

.section {
  max-width: var(--max);
  margin: 0 auto;
  padding: 64px 24px 0;
}

.sec-head { max-width: 560px; }

.eyebrow {
  display: block;
  font-size: 11.5px;
  letter-spacing: .22em;
  text-transform: uppercase;
  color: rgba(160, 200, 255, .58);
}

.sec-head h2 {
  margin-top: 14px;
  font-size: clamp(1.65rem, 3vw, 2.15rem);
  font-weight: 600;
  letter-spacing: -.01em;
  line-height: 1.34;
}

.sec-head p {
  margin-top: 12px;
  font-size: 14.5px;
  color: var(--ink-dim);
}

/* ---------------- 科目卡 ---------------- */

.grid-subjects {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-top: 40px;
}

.subject {
  display: flex;
  flex-direction: column;
  padding: 24px 22px 20px;
  min-height: 236px;
  border-radius: var(--r-lg);
  overflow: hidden;
  transition: transform .45s var(--ease), border-color .45s var(--ease),
              box-shadow .45s var(--ease), background .45s var(--ease);
}

.subject:hover {
  transform: translateY(-5px);
  border-color: rgba(255, 255, 255, .18);
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, .22),
    0 34px 70px -30px rgba(0, 0, 0, 1);
}

.spot {
  position: absolute;
  inset: 0;
  z-index: 1;
  border-radius: inherit;
  opacity: 0;
  transition: opacity .5s var(--ease);
  background: radial-gradient(340px circle at var(--mx, 50%) var(--my, 50%), var(--glow), transparent 66%);
  pointer-events: none;
}

.subject:hover .spot,
.feat:hover .spot { opacity: 1; }

.subject-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: relative;
  z-index: 1;
}

.icon {
  display: grid;
  place-items: center;
  width: 40px;
  height: 40px;
  border-radius: 13px;
  color: var(--c, var(--cyan));
  background: linear-gradient(150deg, rgba(255, 255, 255, .12), rgba(255, 255, 255, .035));
  border: 1px solid rgba(255, 255, 255, .14);
  box-shadow:
    0 8px 22px -12px currentColor,
    inset 0 1px 0 rgba(255, 255, 255, .2);
}

.icon svg { width: 20px; height: 20px; }

.badge {
  font-size: 11px;
  letter-spacing: .08em;
  padding: 4px 10px;
  border-radius: 999px;
  color: var(--ink-faint);
  border: 1px solid rgba(255, 255, 255, .1);
  background: rgba(255, 255, 255, .03);
}

.badge.is-live {
  color: #d8fff4;
  border-color: rgba(127, 240, 208, .3);
  background: rgba(127, 240, 208, .1);
}

.subject h3 {
  position: relative;
  z-index: 1;
  margin-top: 22px;
  font-size: 21px;
  font-weight: 600;
  letter-spacing: .01em;
}

.subject-desc {
  position: relative;
  z-index: 1;
  margin-top: 7px;
  font-size: 13.5px;
  color: var(--ink-faint);
}

.subject-foot {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: auto;
  padding-top: 20px;
}

.meta {
  font-size: 12px;
  color: rgba(238, 242, 248, .46);
  font-variant-numeric: tabular-nums;
}

.arrow {
  font-size: 14px;
  color: rgba(238, 242, 248, .5);
  transition: transform .45s var(--ease), color .45s var(--ease);
}

.subject:hover .arrow {
  transform: translateX(4px);
  color: var(--ink);
}

.subject .index {
  position: absolute;
  right: 16px;
  bottom: 10px;
  z-index: 0;
  font-size: 74px;
  font-weight: 600;
  line-height: 1;
  letter-spacing: -.04em;
  color: rgba(255, 255, 255, .022);
  pointer-events: none;
}

.subject.is-soon { opacity: .78; }
.subject.is-soon:hover { opacity: .95; }

/* ---------------- 特点 ---------------- */

.grid-features {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-top: 40px;
}

.feat {
  padding: 26px 24px 28px;
  border-radius: var(--r-lg);
  overflow: hidden;
  transition: transform .45s var(--ease), border-color .45s var(--ease);
  --glow: rgba(150, 195, 255, .16);
}

.feat:hover {
  transform: translateY(-3px);
  border-color: rgba(255, 255, 255, .16);
}

.feat .icon { color: rgba(200, 225, 255, .8); }

.feat h3 {
  position: relative;
  z-index: 1;
  margin-top: 20px;
  font-size: 16px;
  font-weight: 600;
}

.feat p {
  position: relative;
  z-index: 1;
  margin-top: 10px;
  font-size: 13.5px;
  line-height: 1.75;
  color: var(--ink-dim);
}

/* ---------------- 页脚 ---------------- */

.site-foot {
  flex-shrink: 0;
  width: 100%;
  max-width: var(--max);
  margin: 0 auto;
  padding: 96px 24px 44px;
}

.foot-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 14px 28px;
  padding-top: 26px;
  border-top: 1px solid rgba(255, 255, 255, .07);
}

.foot-brand {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font-size: 13px;
  letter-spacing: .1em;
  color: rgba(238, 242, 248, .78);
}

.foot-inner p {
  font-size: 12.5px;
  color: var(--ink-faint);
}

.foot-note {
  margin-left: auto;
  font-size: 11.5px;
  letter-spacing: .04em;
  color: rgba(238, 242, 248, .38);
}

/* ---------------- Toast ---------------- */

.toast {
  position: fixed;
  left: 50%;
  bottom: 34px;
  z-index: 90;
  transform: translate(-50%, 16px);
  opacity: 0;
  pointer-events: none;
  padding: 12px 20px;
  font-size: 13px;
  color: rgba(238, 242, 248, .92);
  border-radius: 999px;
  background: rgba(20, 24, 34, .72);
  border: 1px solid rgba(255, 255, 255, .14);
  -webkit-backdrop-filter: blur(20px) saturate(160%);
  backdrop-filter: blur(20px) saturate(160%);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, .16), 0 20px 50px -20px rgba(0, 0, 0, .9);
  transition: opacity .35s var(--ease), transform .35s var(--ease);
  white-space: nowrap;
}

.toast.show {
  opacity: 1;
  transform: translate(-50%, 0);
}

/* ---------------- 入场动画 ---------------- */

.js-anim .reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity .9s var(--ease), transform .9s var(--ease);
  transition-delay: var(--d, 0s);
}

.js-anim .reveal.in {
  opacity: 1;
  transform: none;
}

/* ---------------- 响应式 ---------------- */

@media (max-width: 980px) {
  .hero {
    grid-template-columns: 1fr;
    gap: 52px;
    padding-top: 64px;
  }

  .hero-visual { justify-content: center; }

  .preview {
    max-width: 440px;
    transform: none;
    animation: none;
  }

  .float-chip { right: 10px; }

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

  .grid-subjects > :last-child,
  .grid-features > :last-child { grid-column: span 2; }

  .subject { min-height: 210px; }
}

@media (max-width: 720px) {
  .site-head { padding: 12px 14px 0; }
  .nav { padding: 8px 8px 8px 16px; gap: 12px; }
  .nav-links { display: none; }
  .brand-name { font-size: 13.5px; }

  .hero { padding: 44px 20px 4px; gap: 34px; }
  .lede { font-size: 15px; }
  h1 { font-size: clamp(2.2rem, 8.4vw, 2.9rem); }

  .hero-meta { gap: 22px; margin-top: 34px; }
  .hero-meta strong { font-size: 17px; }
  .hero-meta span { font-size: 11px; }

  .section { padding: 64px 20px 0; }

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

  .grid-subjects > :last-child,
  .grid-features > :last-child { grid-column: auto; }

  .preview { padding: 18px; }
  .float-chip { display: none; }

  .subject { min-height: 196px; }

  .site-foot { padding: 68px 20px 36px; }
  .foot-note { margin-left: 0; width: 100%; }
}

@media (max-width: 420px) {
  .btn { padding: 12px 20px; font-size: 14px; }
  .cta-row .btn { flex: 1 1 100%; }
  .hero-meta { flex-wrap: wrap; row-gap: 14px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
  }
  .js-anim .reveal { opacity: 1 !important; transform: none !important; }
}

/* ---------------- 英语题库占位页 ---------------- */

.soon-page {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.soon-head {
  padding: 22px 24px;
}

.soon-head .brand { width: fit-content; }

.soon-main {
  position: relative;
  flex: 1;
  display: grid;
  place-items: center;
  padding: 24px 24px 72px;
}

.soon-main::before {
  content: "";
  position: absolute;
  left: 50%;
  top: 46%;
  width: min(780px, 92vw);
  aspect-ratio: 1 / .78;
  transform: translate(-50%, -50%);
  z-index: -1;
  background:
    radial-gradient(50% 50% at 50% 40%, rgba(96, 150, 240, .26), transparent 72%),
    radial-gradient(40% 40% at 30% 70%, rgba(140, 112, 232, .2), transparent 74%);
  filter: blur(50px);
}

.soon-card {
  width: 100%;
  max-width: 620px;
  padding: 38px 36px 32px;
  border-radius: var(--r-lg);
  overflow: hidden;
}

.soon-card h1 {
  margin-top: 18px;
  font-size: clamp(1.9rem, 4.4vw, 2.6rem);
  line-height: 1.24;
}

.soon-card .lede { margin-top: 14px; font-size: 14.5px; }

.soon-list {
  margin-top: 30px;
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.soon-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 14px 2px;
  border-bottom: 1px solid rgba(255, 255, 255, .06);
  font-size: 13.5px;
}

.soon-row:last-child { border-bottom: 0; }

.soon-row .name { color: rgba(238, 242, 248, .86); }

.soon-row .state {
  font-size: 11.5px;
  letter-spacing: .06em;
  color: var(--ink-faint);
}

.soon-row .state.done { color: #b9ffe9; }
.soon-row .state.doing { color: #cfe8ff; }

.soon-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 28px;
}

.soon-note {
  margin-top: 22px;
  font-size: 12px;
  color: rgba(238, 242, 248, .44);
  letter-spacing: .03em;
}

@media (max-width: 620px) {
  .soon-card { padding: 28px 22px 24px; }
  .soon-actions .btn { flex: 1 1 100%; }
}