/* Phòng khám Tai Mũi Họng (DEMO) - style.css
   Mobile-first từ 360px. Không phông/tài nguyên ngoài. Tham chiếu: design-tmh-demo.md
   Quy ước: .js trên <html> do main.js thêm; menu thu gọn điều khiển bằng aria-expanded. */

:root {
  /* Màu (cặp tương phản ghi trong design-tmh-demo.md, mục 2) */
  --c-bg: #f7fafa;
  --c-surface: #ffffff;
  --c-tint: #eaf4f3;
  --c-text: #1f2d3a;
  --c-heading: #12333a;
  --c-muted: #4a5b68;
  --c-primary: #0b6e73;
  --c-primary-dark: #084f53;
  --c-on-primary: #ffffff;
  --c-accent: #9a3f18;
  --c-border: #d3e1e0;
  --c-input-border: #5e7476;
  --c-demo-bg: #fff1cc;
  --c-demo-text: #4a3300;
  --c-demo-line: #e3c877;
  --c-footer-bg: #12333a;
  --c-footer-text: #e6f1f0;
  --c-footer-muted: #b9d0cf;
  --c-error: #b3261e;
  --c-error-bg: #fdecea;
  --c-success: #1b5e36;
  --c-success-bg: #e6f4ea;
  --c-focus: #1a4fb5;
  --c-focus-dark: #ffd479;

  /* Chữ */
  --font: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif;
  --fs-base: 1rem;
  --fs-lead: 1.125rem;
  --fs-h3: 1.25rem;
  --fs-h2: clamp(1.5rem, 1.2rem + 1.2vw, 2rem);
  --fs-h1: clamp(1.75rem, 1.3rem + 2.2vw, 2.75rem);
  --lh: 1.6;

  /* Khoảng cách, bo góc, bóng */
  --s-1: 0.25rem;
  --s-2: 0.5rem;
  --s-3: 0.75rem;
  --s-4: 1rem;
  --s-5: 1.5rem;
  --s-6: 2rem;
  --s-7: 3rem;
  --s-8: 4.5rem;
  --r-sm: 10px;
  --r-md: 16px;
  --r-lg: 28px;
  --shadow: 0 1px 2px rgba(18, 51, 58, 0.06), 0 6px 18px rgba(18, 51, 58, 0.07);
  --tap: 44px;
  --maxw: 72rem;
}

/* ---------- Nền ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-padding-top: var(--s-4); }
body {
  margin: 0;
  font-family: var(--font);
  font-size: var(--fs-base);
  line-height: var(--lh);
  color: var(--c-text);
  background: var(--c-bg);
}
img, svg { display: block; max-width: 100%; height: auto; }
h1, h2, h3 { color: var(--c-heading); line-height: 1.25; margin: 0 0 var(--s-3); }
h1 { font-size: var(--fs-h1); letter-spacing: -0.01em; }
h2 { font-size: var(--fs-h2); }
h3 { font-size: var(--fs-h3); }
p { margin: 0 0 var(--s-4); max-width: 68ch; }
ul, ol { margin: 0 0 var(--s-4); padding-left: 1.25rem; }
a { color: var(--c-primary); text-underline-offset: 0.2em; }
a:hover { color: var(--c-primary-dark); text-decoration-thickness: 2px; }
[hidden] { display: none !important; }
main:focus { outline: none; }

:focus-visible { outline: 3px solid var(--c-focus); outline-offset: 3px; }
.site-footer :focus-visible, .cta :focus-visible { outline-color: var(--c-focus-dark); }

.container { width: min(100% - 2rem, var(--maxw)); margin-inline: auto; }
.visually-hidden {
  position: absolute !important; width: 1px; height: 1px; margin: -1px; padding: 0;
  overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0;
}
.skip-link {
  position: absolute; left: var(--s-2); top: -5rem; z-index: 100;
  min-height: var(--tap); display: inline-flex; align-items: center; padding: 0 var(--s-4);
  background: var(--c-heading); color: #fff; font-weight: 700; border-radius: var(--r-sm);
}
.skip-link:focus { top: var(--s-2); color: #fff; }

/* ---------- Dải demo (FR-01) ---------- */
.demo-banner {
  background: var(--c-demo-bg); color: var(--c-demo-text);
  border-bottom: 1px solid var(--c-demo-line); line-height: 1.4;
}
.demo-banner .container { padding-block: var(--s-2); display: flex; flex-wrap: wrap; gap: 0 var(--s-2); align-items: baseline; }
.demo-banner strong { text-transform: uppercase; letter-spacing: 0.04em; }

/* ---------- Header và điều hướng (FR-02) ---------- */
.site-header { background: var(--c-surface); border-bottom: 1px solid var(--c-border); }
.header-inner { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: var(--s-2) var(--s-4); padding-block: var(--s-2); }
.brand {
  display: inline-flex; align-items: center; gap: var(--s-3); min-height: var(--tap);
  color: var(--c-heading); font-weight: 700; font-size: 1.0625rem; line-height: 1.2; text-decoration: none;
}
.brand:hover { color: var(--c-primary-dark); }
.brand img { width: 40px; height: 40px; flex: none; }

.nav-toggle { display: none; }
.js .nav-toggle {
  display: inline-flex; align-items: center; gap: var(--s-2); min-height: var(--tap); min-width: var(--tap);
  padding: 0 var(--s-4); font: inherit; font-weight: 700; color: var(--c-heading);
  background: var(--c-surface); border: 2px solid var(--c-primary); border-radius: 999px; cursor: pointer;
}
.nav-toggle-bars, .nav-toggle-bars::before, .nav-toggle-bars::after {
  display: block; width: 18px; height: 2px; background: currentColor; border-radius: 2px; content: ""; position: relative;
}
.nav-toggle-bars::before { position: absolute; top: -6px; }
.nav-toggle-bars::after { position: absolute; top: 6px; }
.nav-toggle[aria-expanded="true"] .nav-toggle-bars { background: transparent; }
.nav-toggle[aria-expanded="true"] .nav-toggle-bars::before { top: 0; transform: rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle-bars::after { top: 0; transform: rotate(-45deg); }

.site-nav { flex-basis: 100%; }
.js .nav-toggle[aria-expanded="false"] ~ .site-nav { display: none; }
.site-nav ul { list-style: none; margin: 0; padding: 0 0 var(--s-2); display: grid; gap: var(--s-1); }
.site-nav a {
  display: flex; align-items: center; min-height: var(--tap); padding: var(--s-2) var(--s-4);
  border-radius: var(--r-sm); color: var(--c-text); font-weight: 600; text-decoration: none;
}
.site-nav a:hover { background: var(--c-tint); color: var(--c-primary-dark); }
.site-nav a[aria-current="page"] { background: var(--c-tint); color: var(--c-primary-dark); box-shadow: inset 4px 0 0 var(--c-primary); }

/* ---------- Nút ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: var(--s-2);
  min-height: 48px; min-width: var(--tap); padding: 0 var(--s-5);
  font: inherit; font-weight: 700; line-height: 1.2; text-align: center; text-decoration: none; cursor: pointer;
  border: 2px solid transparent; border-radius: 999px;
  transition: background-color 0.18s ease, color 0.18s ease, border-color 0.18s ease;
}
.btn--primary { background: var(--c-primary); color: var(--c-on-primary); }
.btn--primary:hover { background: var(--c-primary-dark); color: var(--c-on-primary); }
.btn--secondary { background: var(--c-surface); color: var(--c-primary-dark); border-color: var(--c-primary); }
.btn--secondary:hover { background: var(--c-tint); color: var(--c-primary-dark); }
.btn--light { background: #fff; color: var(--c-primary-dark); }
.btn--light:hover { background: var(--c-tint); color: var(--c-primary-dark); }
.btn-row { display: flex; flex-wrap: wrap; gap: var(--s-3); }

/* ---------- Khối trang ---------- */
.section { padding-block: var(--s-7); }
.section--tint { background: var(--c-tint); }
.section-head { margin-bottom: var(--s-6); }
.section-head p { color: var(--c-muted); }
.eyebrow { margin: 0 0 var(--s-2); color: var(--c-accent); font-weight: 700; text-transform: uppercase; letter-spacing: 0.06em; font-size: 0.9375rem; }
.lead { font-size: var(--fs-lead); }
.muted { color: var(--c-muted); }
.badge { display: inline-block; padding: 0 var(--s-3); border-radius: 999px; background: var(--c-demo-bg); color: var(--c-demo-text); font-size: 0.875rem; font-weight: 700; }
.note { padding: var(--s-4); background: var(--c-surface); border-left: 4px solid var(--c-accent); border-radius: var(--r-sm); }

.hero { background: linear-gradient(180deg, var(--c-tint) 0%, var(--c-bg) 100%); padding-block: var(--s-7) var(--s-8); }
.hero-inner { display: grid; gap: var(--s-6); align-items: center; }
.hero-art img { width: 100%; max-width: 34rem; margin-inline: auto; }
.page-hero { background: var(--c-tint); padding-block: var(--s-6); }
.page-hero p { margin-bottom: 0; color: var(--c-muted); }

.grid { display: grid; gap: var(--s-5); }

.card {
  position: relative; background: var(--c-surface); border: 1px solid var(--c-border);
  border-radius: var(--r-md); padding: var(--s-5); box-shadow: var(--shadow);
}
.card > :last-child { margin-bottom: 0; }

/* Thẻ dịch vụ */
.service-card { display: flex; flex-direction: column; gap: var(--s-2); transition: transform 0.2s ease, box-shadow 0.2s ease; }
.service-card:hover { transform: translateY(-3px); }
.service-card img { width: 56px; height: 56px; margin-bottom: var(--s-2); }
.service-card h3 { margin-bottom: 0; }
.service-card p { color: var(--c-muted); margin-bottom: var(--s-2); }
.service-card a { font-weight: 700; text-decoration: none; }
.service-card a:hover { text-decoration: underline; }
.service-card a::after { content: ""; position: absolute; inset: 0; border-radius: var(--r-md); } /* cả thẻ là vùng chạm */
.service-card a:focus-visible { outline: none; }
.service-card a:focus-visible::after { outline: 3px solid var(--c-focus); outline-offset: 3px; }

/* Hồ sơ bác sĩ */
.doctor-card { display: grid; grid-template-columns: 88px 1fr; gap: var(--s-4); align-items: start; }
.doctor-card img { width: 88px; height: 88px; border-radius: 50%; }
.doctor-card h3 { margin-bottom: var(--s-1); }
.doctor-role { margin: 0 0 var(--s-2); color: var(--c-primary-dark); font-weight: 700; }
.meta { margin: 0; display: grid; gap: var(--s-2); }
.meta dt { font-size: 0.875rem; font-weight: 700; color: var(--c-muted); text-transform: uppercase; letter-spacing: 0.04em; }
.meta dd { margin: 0; }

/* Điểm nổi bật, giá trị */
.feature { padding: var(--s-4) 0 0; border-top: 4px solid var(--c-primary); }
.feature h3 { margin-bottom: var(--s-2); }
.feature p { margin-bottom: 0; color: var(--c-muted); }
.feature-list { list-style: none; margin: 0; padding: 0; }

/* Cơ sở vật chất */
.facility { margin: 0; background: var(--c-surface); border: 1px solid var(--c-border); border-radius: var(--r-md); overflow: hidden; box-shadow: var(--shadow); }
.facility img { width: 100%; aspect-ratio: 4 / 3; object-fit: cover; background: var(--c-tint); }
.facility figcaption { padding: var(--s-4) var(--s-5) var(--s-5); }
.facility figcaption strong { display: block; color: var(--c-heading); font-size: var(--fs-h3); margin-bottom: var(--s-1); }

/* Bảng giờ làm việc */
.table-wrap { overflow-x: auto; }
.hours { width: 100%; border-collapse: collapse; background: var(--c-surface); border: 1px solid var(--c-border); border-radius: var(--r-sm); }
.hours caption { padding: var(--s-3) 0; text-align: left; font-weight: 700; color: var(--c-heading); }
.hours th, .hours td { padding: var(--s-3) var(--s-4); text-align: left; border-bottom: 1px solid var(--c-border); }
.hours thead th { background: var(--c-tint); color: var(--c-heading); }
.hours tbody th { font-weight: 600; }

/* Liên hệ */
.contact-list { margin: 0; display: grid; gap: var(--s-4); }
.contact-list dt { font-weight: 700; color: var(--c-heading); }
.contact-list dd { margin: 0; overflow-wrap: anywhere; }
.contact-list a { display: inline-flex; align-items: center; min-height: var(--tap); }
.map-figure { margin: 0; }
.map-figure img { width: 100%; border: 1px solid var(--c-border); border-radius: var(--r-md); background: var(--c-surface); }
.map-figure figcaption { margin-top: var(--s-2); color: var(--c-muted); }

/* Biểu mẫu đặt lịch (FR-08) */
.form { display: grid; gap: var(--s-5); }
.field label { display: block; margin-bottom: var(--s-1); font-weight: 600; color: var(--c-heading); }
.field .req { color: var(--c-error); font-weight: 700; }
.field-hint { margin: 0 0 var(--s-1); color: var(--c-muted); }
.field input, .field select, .field textarea {
  display: block; width: 100%; min-height: 48px; padding: var(--s-3) var(--s-4);
  font: inherit; color: var(--c-text); background: var(--c-surface);
  border: 2px solid var(--c-input-border); border-radius: var(--r-sm);
}
.field textarea { min-height: 7.5rem; resize: vertical; }
.field input:focus-visible, .field select:focus-visible, .field textarea:focus-visible { outline: 3px solid var(--c-focus); outline-offset: 2px; border-color: var(--c-focus); }
.field [aria-invalid="true"] { border-color: var(--c-error); background: var(--c-error-bg); }
.field-error { margin: var(--s-1) 0 0; color: var(--c-error); font-weight: 700; }
.field-error::before { content: "Lỗi: "; }
.alert { padding: var(--s-4) var(--s-5); border-radius: var(--r-sm); border: 2px solid; font-weight: 600; }
.alert--success { background: var(--c-success-bg); color: var(--c-success); border-color: var(--c-success); }

/* Khối kêu gọi */
.cta { background: var(--c-primary-dark); color: #fff; border-radius: var(--r-lg); padding: var(--s-6) var(--s-5); }
.cta h2 { color: #fff; }
.cta p { color: #fff; }

/* ---------- Footer ---------- */
.site-footer { background: var(--c-footer-bg); color: var(--c-footer-text); padding-block: var(--s-7) var(--s-5); }
.site-footer h2 { color: #fff; font-size: var(--fs-h3); }
.site-footer a { color: var(--c-footer-text); display: inline-flex; align-items: center; min-height: var(--tap); }
.site-footer a:hover { color: #fff; text-decoration-thickness: 2px; }
.site-footer ul { list-style: none; margin: 0; padding: 0; }
.site-footer p { color: var(--c-footer-muted); }
.footer-grid { display: grid; gap: var(--s-6); }
.footer-demo { margin: var(--s-6) 0 0; padding-top: var(--s-4); border-top: 1px solid rgba(230, 241, 240, 0.25); color: var(--c-footer-text); font-weight: 600; max-width: none; }

/* ---------- Màn hình rộng ---------- */
@media (min-width: 600px) {
  .grid--2, .grid--3, .grid--4 { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: repeat(2, 1fr); }
  .cta { padding: var(--s-7) var(--s-6); }
}
@media (min-width: 768px) {
  .section { padding-block: var(--s-8); }
  .page-hero { padding-block: var(--s-7); }
  .js .nav-toggle { display: none; }
  .js .nav-toggle[aria-expanded="false"] ~ .site-nav { display: block; }
  .site-nav { flex-basis: auto; }
  .site-nav ul { display: flex; gap: var(--s-1); padding: 0; }
  .site-nav a[aria-current="page"] { background: transparent; box-shadow: inset 0 -4px 0 var(--c-primary); border-radius: var(--r-sm) var(--r-sm) 0 0; }
  .site-nav a[aria-current="page"]:hover { background: var(--c-tint); }
}
@media (min-width: 960px) {
  .hero-inner { grid-template-columns: 1.1fr 1fr; }
  .grid--3 { grid-template-columns: repeat(3, 1fr); }
  .grid--4 { grid-template-columns: repeat(4, 1fr); }
  .footer-grid { grid-template-columns: 1.4fr 1fr 1fr; }
  .contact-layout { display: grid; grid-template-columns: 1fr 1.2fr; gap: var(--s-6); align-items: start; }
}

/* ---------- Giảm chuyển động ---------- */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { transition: none !important; animation: none !important; scroll-behavior: auto !important; }
  .service-card:hover { transform: none; }
}