/* 本地字体（替代 Google Fonts，国内可正常加载） */
@font-face{font-family:'Fraunces';font-style:normal;font-weight:100 900;font-display:swap;src:url(fonts/fraunces-latin-opsz-normal.woff2) format('woff2-variations');unicode-range:U+0000-00FF,U+0131,U+0152-0153,U+02BB-02BC,U+02C6,U+02DA,U+02DC,U+0304,U+0308,U+0329,U+2000-206F,U+20AC,U+2122,U+2191,U+2193,U+2212,U+2215,U+FEFF,U+FFFD;}
@font-face{font-family:'Inter';font-style:normal;font-weight:400;font-display:swap;src:url(fonts/inter-latin-400-normal.woff2) format('woff2');unicode-range:U+0000-00FF,U+0131,U+0152-0153,U+02BB-02BC,U+02C6,U+02DA,U+02DC,U+0304,U+0308,U+0329,U+2000-206F,U+20AC,U+2122,U+2191,U+2193,U+2212,U+2215,U+FEFF,U+FFFD;}
@font-face{font-family:'Inter';font-style:normal;font-weight:500;font-display:swap;src:url(fonts/inter-latin-500-normal.woff2) format('woff2');unicode-range:U+0000-00FF,U+0131,U+0152-0153,U+02BB-02BC,U+02C6,U+02DA,U+02DC,U+0304,U+0308,U+0329,U+2000-206F,U+20AC,U+2122,U+2191,U+2193,U+2212,U+2215,U+FEFF,U+FFFD;}
@font-face{font-family:'Inter';font-style:normal;font-weight:600;font-display:swap;src:url(fonts/inter-latin-600-normal.woff2) format('woff2');unicode-range:U+0000-00FF,U+0131,U+0152-0153,U+02BB-02BC,U+02C6,U+02DA,U+02DC,U+0304,U+0308,U+0329,U+2000-206F,U+20AC,U+2122,U+2191,U+2193,U+2212,U+2215,U+FEFF,U+FFFD;}
@font-face{font-family:'IBM Plex Mono';font-style:normal;font-weight:400;font-display:swap;src:url(fonts/ibm-plex-mono-latin-400-normal.woff2) format('woff2');unicode-range:U+0000-00FF,U+0131,U+0152-0153,U+02BB-02BC,U+02C6,U+02DA,U+02DC,U+0304,U+0308,U+0329,U+2000-206F,U+20AC,U+2122,U+2191,U+2193,U+2212,U+2215,U+FEFF,U+FFFD;}
@font-face{font-family:'IBM Plex Mono';font-style:normal;font-weight:500;font-display:swap;src:url(fonts/ibm-plex-mono-latin-500-normal.woff2) format('woff2');unicode-range:U+0000-00FF,U+0131,U+0152-0153,U+02BB-02BC,U+02C6,U+02DA,U+02DC,U+0304,U+0308,U+0329,U+2000-206F,U+20AC,U+2122,U+2191,U+2193,U+2212,U+2215,U+FEFF,U+FFFD;}
.footer-bottom a{color:inherit;text-decoration:none}.footer-bottom a:hover{text-decoration:underline}

/* ==========================================================================
   奥弗留学 — Design tokens
   Concept: official-document aesthetic — paper, hairline rule, ink stamp.
   专注美国留学申请 — 美高 / 美本 / 美研, each milestone "盖章生效" (stamped, sealed, valid).
   ========================================================================== */

:root {
  --ink: #16161a;
  --ink-soft: #3a3936;
  --paper: #f6f4ef;
  --paper-alt: #efebe1;
  --paper-deep: #e7e2d4;
  --gray: #716d65;
  --line: #d8d2c2;
  --stamp: #9a3324;
  --stamp-dark: #762417;
  --stamp-soft: rgba(154, 51, 36, 0.08);

  --font-display: "Fraunces", "Songti SC", serif;
  --font-body: "Inter", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-mono: "IBM Plex Mono", "Noto Sans Mono", monospace;

  --container: 1180px;
  --radius: 2px;

  --ease: cubic-bezier(0.22, 1, 0.36, 1);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 600;
  line-height: 1.18;
  margin: 0 0 0.5em;
  letter-spacing: -0.01em;
}

p { margin: 0 0 1em; color: var(--ink-soft); }

.container {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 32px;
}

.eyebrow {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--stamp);
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 18px;
}
.eyebrow::before {
  content: "";
  width: 22px;
  height: 1px;
  background: var(--stamp);
}

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(246, 244, 239, 0.92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
}
.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 76px;
}
.logo {
  font-family: var(--font-display);
  font-size: 22px;
  font-weight: 600;
  display: flex;
  align-items: baseline;
  gap: 6px;
}
.logo .mark { color: var(--stamp); }
.logo .sub {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--gray);
  letter-spacing: 0.1em;
  margin-left: 4px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 40px;
  list-style: none;
  margin: 0;
  padding: 0;
}
.nav-links a {
  font-size: 14px;
  color: var(--ink-soft);
  position: relative;
  padding: 4px 0;
  transition: color 0.2s var(--ease);
}
.nav-links a:hover { color: var(--ink); }
.nav-links a::after {
  content: "";
  position: absolute;
  left: 0; right: 100%;
  bottom: 0;
  height: 1px;
  background: var(--stamp);
  transition: right 0.25s var(--ease);
}
.nav-links a:hover::after,
.nav-links a.active::after { right: 0; }
.nav-links a.active { color: var(--stamp); }

.nav-cta {
  display: flex;
  align-items: center;
  gap: 24px;
}

.menu-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}
.menu-toggle span {
  width: 22px; height: 1px;
  background: var(--ink);
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.04em;
  padding: 13px 26px;
  border: 1px solid var(--ink);
  border-radius: var(--radius);
  cursor: pointer;
  transition: all 0.25s var(--ease);
  white-space: nowrap;
}
.btn-primary {
  background: var(--ink);
  color: var(--paper);
}
.btn-primary:hover {
  background: var(--stamp);
  border-color: var(--stamp);
}
.btn-ghost {
  background: transparent;
  color: var(--ink);
}
.btn-ghost:hover {
  border-color: var(--stamp);
  color: var(--stamp);
}
.btn-stamp {
  border: 1px solid var(--stamp);
  color: var(--stamp);
  background: var(--stamp-soft);
}
.btn-stamp:hover {
  background: var(--stamp);
  color: var(--paper);
}

/* ---------- Stamp signature element ---------- */
.stamp {
  --size: 132px;
  width: var(--size);
  height: var(--size);
  border-radius: 50%;
  border: 1.5px dashed var(--stamp);
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  color: var(--stamp);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  transform: rotate(-9deg);
  position: relative;
  flex-shrink: 0;
  transition: transform 0.4s var(--ease);
}
.stamp::before {
  content: "";
  position: absolute;
  inset: 10px;
  border: 1px solid var(--stamp);
  border-radius: 50%;
  opacity: 0.5;
}
.stamp:hover { transform: rotate(-3deg) scale(1.04); }
.stamp .stamp-line1 { font-weight: 600; font-size: 13px; margin-bottom: 4px; }
.stamp .stamp-line2 { opacity: 0.8; }

/* ---------- Hero ---------- */
.hero {
  padding: 90px 0 110px;
  border-bottom: 1px solid var(--line);
  position: relative;
  overflow: hidden;
}
.hero-grid {
  display: grid;
  grid-template-columns: 1.4fr 0.6fr;
  gap: 60px;
  align-items: end;
}
.hero h1 {
  font-size: clamp(36px, 5vw, 58px);
  max-width: 16ch;
}
.hero .lede {
  font-size: 18px;
  max-width: 46ch;
  color: var(--ink-soft);
  margin-bottom: 36px;
}
.hero-actions { display: flex; gap: 16px; flex-wrap: wrap; }
.hero-aside {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 18px;
}

/* MRZ-style decorative strip, nods to passport machine-readable zone */
.mrz {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--gray);
  opacity: 0.55;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  border-top: 1px solid var(--line);
  padding-top: 14px;
  margin-top: 28px;
}

/* ---------- Stat row ---------- */
.stats {
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}
.stats .container {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
}
.stat {
  padding: 32px 28px;
  border-left: 1px solid var(--line);
}
.stat:first-child { border-left: none; }
.stat .num {
  font-family: var(--font-display);
  font-size: 36px;
  color: var(--stamp);
}
.stat .label {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--gray);
  letter-spacing: 0.04em;
  margin-top: 6px;
}

/* ---------- Sections ---------- */
section.block { padding: 96px 0; }
section.block.alt { background: var(--paper-alt); }
.section-head {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  gap: 40px;
  margin-bottom: 56px;
}
.section-head h2 { font-size: clamp(28px, 3.4vw, 40px); max-width: 14ch; }
.section-head .note { max-width: 38ch; font-size: 15px; }

/* ---------- Process steps ---------- */
.process {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}
.process-step {
  background: var(--paper);
  padding: 36px 28px;
  position: relative;
}
.process-step .step-no {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--stamp);
  letter-spacing: 0.08em;
  margin-bottom: 22px;
  display: block;
}
.process-step h3 { font-size: 19px; margin-bottom: 10px; }
.process-step p { font-size: 14px; margin-bottom: 0; }

/* ---------- Cards ---------- */
.card-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}
.card {
  border: 1px solid var(--line);
  padding: 36px 30px;
  background: var(--paper);
  transition: border-color 0.25s var(--ease), transform 0.25s var(--ease);
}
.card:hover { border-color: var(--stamp); transform: translateY(-3px); }
.card h3 { font-size: 20px; margin-bottom: 12px; }
.card p { font-size: 14.5px; }
.card-icon {
  width: 40px; height: 40px;
  border: 1px solid var(--stamp);
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  color: var(--stamp);
  font-family: var(--font-mono);
  font-size: 13px;
  margin-bottom: 24px;
}
.card-list {
  list-style: none;
  margin: 16px 0 0;
  padding: 0;
  font-size: 14px;
  color: var(--ink-soft);
}
.card-list li {
  padding: 9px 0;
  border-top: 1px solid var(--line);
  display: flex;
  justify-content: space-between;
  gap: 12px;
}
.card-list li::before {
  content: "·";
  color: var(--stamp);
  margin-right: 8px;
}

/* ---------- Case cards ---------- */
.case-card {
  border: 1px solid var(--line);
  background: var(--paper);
  padding: 30px;
  position: relative;
}
.case-top {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 20px;
}
.case-tag {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--gray);
  letter-spacing: 0.06em;
}
.case-offer {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--stamp);
  border: 1px solid var(--stamp);
  padding: 4px 10px;
  border-radius: 999px;
  transform: rotate(-4deg);
  white-space: nowrap;
}
.case-card h3 { font-size: 19px; }
.case-meta {
  font-family: var(--font-mono);
  font-size: 12.5px;
  color: var(--gray);
  margin-bottom: 14px;
}

/* ---------- CTA banner ---------- */
.cta-banner {
  background: var(--ink);
  color: var(--paper);
  padding: 80px 0;
  text-align: center;
}
.cta-banner h2 {
  color: var(--paper);
  font-size: clamp(26px, 3.6vw, 38px);
  margin-bottom: 20px;
}
.cta-banner p { color: #c9c6bd; margin-bottom: 36px; }
.cta-banner .btn-primary { background: var(--stamp); border-color: var(--stamp); color: var(--paper); }
.cta-banner .btn-primary:hover { background: var(--paper); color: var(--ink); border-color: var(--paper); }
.cta-banner .btn-ghost { color: var(--paper); border-color: #5b594f; }
.cta-banner .btn-ghost:hover { border-color: var(--paper); color: var(--paper); }
.cta-banner .actions { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }

/* ---------- Footer ---------- */
.site-footer {
  border-top: 1px solid var(--line);
  padding: 64px 0 32px;
}
.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 48px;
}
.footer-grid h4 {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--gray);
  text-transform: uppercase;
  margin-bottom: 18px;
}
.footer-grid ul { list-style: none; margin: 0; padding: 0; }
.footer-grid li { margin-bottom: 10px; font-size: 14px; }
.footer-grid a:hover { color: var(--stamp); }
.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-top: 1px solid var(--line);
  padding-top: 24px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--gray);
  flex-wrap: wrap;
  gap: 12px;
}

/* ---------- Reveal-on-scroll ---------- */
.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.7s var(--ease), transform 0.7s var(--ease);
}
.reveal.is-visible { opacity: 1; transform: translateY(0); }

/* ---------- Page header (inner pages) ---------- */
.page-header {
  padding: 64px 0 56px;
  border-bottom: 1px solid var(--line);
}
.page-header h1 { font-size: clamp(32px, 4.2vw, 46px); max-width: 18ch; }
.page-header .lede { font-size: 16px; max-width: 50ch; }

/* ---------- About page specifics ---------- */
.value-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}
.split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
}
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 56px;
}
.contact-list { list-style: none; margin: 0; padding: 0; }
.contact-list li {
  display: flex;
  gap: 16px;
  padding: 18px 0;
  border-top: 1px solid var(--line);
}
.contact-list li:last-child { border-bottom: 1px solid var(--line); }
.contact-list .k {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--gray);
  width: 90px;
  flex-shrink: 0;
  letter-spacing: 0.04em;
}
.contact-list .v { font-size: 15px; }

.placeholder-note {
  font-family: var(--font-mono);
  font-size: 11.5px;
  color: var(--gray);
  background: var(--paper-alt);
  border: 1px dashed var(--line);
  padding: 10px 14px;
  margin-top: 6px;
}

form.inquiry {
  display: flex;
  flex-direction: column;
  gap: 18px;
}
form.inquiry label {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--gray);
  letter-spacing: 0.04em;
  display: block;
  margin-bottom: 8px;
}
form.inquiry input,
form.inquiry select,
form.inquiry textarea {
  width: 100%;
  border: 1px solid var(--line);
  background: var(--paper);
  padding: 12px 14px;
  font-family: var(--font-body);
  font-size: 14px;
  color: var(--ink);
  border-radius: var(--radius);
}
form.inquiry input:focus,
form.inquiry select:focus,
form.inquiry textarea:focus {
  outline: none;
  border-color: var(--stamp);
}
form.inquiry textarea { resize: vertical; min-height: 110px; }

/* ---------- Focus visibility ---------- */
a:focus-visible, button:focus-visible, input:focus-visible, textarea:focus-visible {
  outline: 2px solid var(--stamp);
  outline-offset: 2px;
}

/* ---------- Responsive ---------- */
@media (max-width: 980px) {
  .hero-grid { grid-template-columns: 1fr; }
  .hero-aside { align-items: flex-start; }
  .stats .container { grid-template-columns: repeat(2, 1fr); }
  .process { grid-template-columns: repeat(2, 1fr); }
  .card-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .split, .contact-grid { grid-template-columns: 1fr; gap: 36px; }
}

@media (max-width: 720px) {
  .nav-links, .nav-cta .btn-ghost { display: none; }
  .menu-toggle { display: flex; }
  .nav-cta { gap: 0; }
  .site-header.open .nav-links {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 76px; left: 0; right: 0;
    background: var(--paper);
    border-bottom: 1px solid var(--line);
    padding: 24px 32px;
    gap: 20px;
  }
  .stats .container { grid-template-columns: repeat(2, 1fr); }
  .process { grid-template-columns: 1fr; }
  .card-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 28px; }
  .section-head { flex-direction: column; align-items: flex-start; gap: 16px; }
}