/* Say Piano Gia sư – giao diện web (giasu.saypiano.com).
 * Màu chép từ khối :root của SayMePiano/prototype/assets/css/thuong-hieu.css (nguồn màu duy nhất; SUMMARY.MD mục 4).
 * Kiểu Apple: nền trung tính, MỘT nút chính Hồng Say mỗi màn, chế độ tối theo máy, không quầng sáng quanh nút.
 * Tiêu đề, nút, giá: Lilita One Viet; nội dung: Quicksand. Vàng Piano chỉ cho thành tích / sao. */
@font-face { font-family: "Lilita One Viet"; src: url("../fonts/LilitaOne-Viet.woff2") format("woff2"); font-display: swap; }
@font-face { font-family: "Quicksand"; src: url("../fonts/Quicksand-Medium.woff2") format("woff2"); font-weight: 500; font-display: swap; }
@font-face { font-family: "Quicksand"; src: url("../fonts/Quicksand-SemiBold.woff2") format("woff2"); font-weight: 600; font-display: swap; }
@font-face { font-family: "Quicksand"; src: url("../fonts/Quicksand-Bold.woff2") format("woff2"); font-weight: 700; font-display: swap; }

:root {
  --sm-dem: #2A0A7E; --sm-khoi: #5B2BC4; --sm-hong: #FF5FAE; --sm-hong-kem: #FFE3E6; --sm-vang: #FFC928;
  --sm-cam: #FF8A00; --sm-ngoc: #22AEFF; --sm-oai: #F1E9FF;
  --sm-hong-dam: #D92B83; --sm-hong-sau: #C2186F; --sm-vang-chu: #7A5600; --sm-vang-nhat: #FFF6D6; --sm-ngoc-chu: #0A68AD;

  --nen: #F7F5FA; --mat: #FFFFFF; --mat-2: #FAF8FD; --vien: rgba(42, 10, 126, .10); --vien-dam: rgba(42, 10, 126, .2);
  --chu: #1E1236; --chu-2: rgba(30, 18, 54, .70); --chu-3: rgba(30, 18, 54, .52);
  --tieu-de: var(--sm-dem); --nhan: var(--sm-khoi); --nhan-nhat: rgba(91, 43, 196, .10);
  --cta: var(--sm-hong-dam); --cta-hover: var(--sm-hong-sau); --lien-ket: var(--sm-ngoc-chu);
  --tot: #1E7A3C; --tot-nen: rgba(52, 199, 89, .14); --canh-bao: #9A4306; --canh-bao-nen: #FFF1E0;
  --loi: #C0123C; --loi-nen: #FFE3E6;
  --bong: 0 1px 2px rgba(42, 10, 126, .05), 0 6px 20px rgba(42, 10, 126, .06);
  --r: 18px; --r-sm: 12px;
  --chu-de: "Lilita One Viet", "Quicksand", system-ui, sans-serif;
  --chu-than: "Quicksand", -apple-system, system-ui, "Segoe UI", sans-serif;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --nen: #0F0B1A; --mat: #1B1628; --mat-2: #221C32; --vien: rgba(241, 233, 255, .10); --vien-dam: rgba(241, 233, 255, .2);
    --chu: #F4EFFF; --chu-2: rgba(244, 239, 255, .72); --chu-3: rgba(244, 239, 255, .5);
    --tieu-de: #F1E9FF; --nhan: #B9A6F0; --nhan-nhat: rgba(185, 166, 240, .14); --lien-ket: #8FD6FF;
    --tot: #5EDB86; --tot-nen: rgba(48, 209, 88, .16); --canh-bao: #FFB13B; --canh-bao-nen: rgba(255, 138, 0, .16);
    --loi: #FF8FA8; --loi-nen: rgba(255, 95, 174, .14); --sm-vang-nhat: rgba(255, 201, 40, .14); --sm-vang-chu: #FFE07A;
    --bong: 0 0 0 .5px rgba(255, 255, 255, .06);
    color-scheme: dark;
  }
}

* { box-sizing: border-box; }
html, body { margin: 0; }
body { font: 500 16px/1.55 var(--chu-than); color: var(--chu); background: var(--nen); -webkit-font-smoothing: antialiased; }
a { color: var(--lien-ket); text-decoration: none; }
a:hover { text-decoration: underline; }
button, input, select, textarea { font: inherit; color: inherit; }
h1, h2, h3 { font-family: var(--chu-de); font-weight: 400; color: var(--tieu-de); letter-spacing: .005em; text-wrap: balance; margin: 0; }
h1 { font-size: clamp(30px, 4.4vw, 46px); line-height: 1.1; }
h2 { font-size: 24px; line-height: 1.2; }
h3 { font-size: 18px; }
p { text-wrap: pretty; }
.mo { color: var(--chu-3); }
.phu { color: var(--chu-2); }
.an { display: none !important; }
:focus-visible { outline: 3px solid rgba(91, 43, 196, .45); outline-offset: 2px; border-radius: 8px; }

/* ---------- thanh trên ---------- */
.dau { position: sticky; top: 0; z-index: 30; background: color-mix(in srgb, var(--nen) 82%, transparent);
  -webkit-backdrop-filter: saturate(180%) blur(18px); backdrop-filter: saturate(180%) blur(18px); border-bottom: .5px solid var(--vien); }
.dau__trong { max-width: 1200px; margin: 0 auto; padding: 10px 16px; display: flex; align-items: center; gap: 14px; }
.dau__logo { display: flex; align-items: center; gap: 10px; text-decoration: none !important; }
.dau__logo img { height: 34px; width: auto; display: block; }
.dau__nhan { font: 400 15px var(--chu-de); color: var(--sm-dem); background: var(--sm-oai); padding: 3px 10px; border-radius: 999px; }
.dau__menu { margin-left: auto; display: flex; align-items: center; gap: 4px; flex-wrap: wrap; justify-content: flex-end; }
.dau__menu a { color: var(--chu-2); font-weight: 600; font-size: 15px; padding: 8px 12px; border-radius: 10px; }
.dau__menu a:hover { background: var(--nhan-nhat); text-decoration: none; color: var(--tieu-de); }
.dau__menu a.dang-o { color: var(--tieu-de); background: var(--nhan-nhat); }
.dau__logo img.logo-trang { display: none; }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .dau__logo img.logo-mau { display: none; }
  :root:not([data-theme="light"]) .dau__logo img.logo-trang { display: block; }
}

main { max-width: 1200px; margin: 0 auto; padding: 24px 16px 80px; }

/* ---------- nút: một hệ duy nhất ---------- */
.nut { display: inline-flex; align-items: center; justify-content: center; gap: 8px; min-height: 44px; padding: 0 20px; border-radius: 12px;
  border: 1.5px solid var(--vien-dam); background: var(--mat); color: var(--nhan); font: 400 17px var(--chu-de); letter-spacing: .01em;
  cursor: pointer; text-decoration: none !important; white-space: nowrap; transition: background .15s, transform .05s; }
.nut:hover { background: var(--nhan-nhat); }
.nut:active { transform: translateY(1px); }
.nut[disabled] { opacity: .5; cursor: not-allowed; }
.nut--chinh { background: var(--cta); border-color: var(--cta); color: #fff; }
.nut--chinh:hover { background: var(--cta-hover); border-color: var(--cta-hover); }
.nut--nhe { border-color: transparent; background: transparent; }
.nut--nho { min-height: 36px; padding: 0 14px; font-size: 15px; border-radius: 10px; }
.nut--rong { width: 100%; }
.nut--nguy { color: var(--loi); }

/* ---------- ô nhập ---------- */
.o { width: 100%; min-height: 44px; padding: 10px 14px; border-radius: 12px; border: 1.5px solid var(--vien-dam); background: var(--mat); font-weight: 600; }
textarea.o { min-height: 96px; resize: vertical; line-height: 1.5; }
.nhan-o { display: block; font-weight: 700; font-size: 14px; color: var(--chu-2); margin: 14px 0 6px; }
.goi-y { font-size: 13px; color: var(--chu-3); margin-top: 4px; }

/* ---------- thẻ ---------- */
.the { background: var(--mat); border-radius: var(--r); box-shadow: var(--bong); border: .5px solid var(--vien); padding: 20px; }
.chip { display: inline-flex; align-items: center; gap: 4px; padding: 3px 10px; border-radius: 999px; font-size: 13px; font-weight: 700;
  background: var(--nhan-nhat); color: var(--nhan); white-space: nowrap; }
.chip--vang { background: var(--sm-vang-nhat); color: var(--sm-vang-chu); }
.chip--tot { background: var(--tot-nen); color: var(--tot); }
.chip--canh-bao { background: var(--canh-bao-nen); color: var(--canh-bao); }
.chip--loi { background: var(--loi-nen); color: var(--loi); }
.chips { display: flex; flex-wrap: wrap; gap: 6px; }

/* ---------- đầu trang tìm gia sư ---------- */
.mo-dau { display: grid; grid-template-columns: 1.2fr 1fr; gap: 32px; align-items: center; padding: 20px 0 28px; }
.mo-dau p { font-size: 18px; color: var(--chu-2); margin: 14px 0 0; max-width: 560px; }
.cam-ket { display: grid; gap: 10px; }
.cam-ket__muc { display: flex; gap: 12px; align-items: flex-start; background: var(--mat); border-radius: var(--r-sm); padding: 14px 16px; border: .5px solid var(--vien); }
.cam-ket__so { flex: none; width: 32px; height: 32px; border-radius: 10px; display: grid; place-items: center; font: 400 17px var(--chu-de);
  background: var(--sm-oai); color: var(--sm-dem); }
.cam-ket__muc b { display: block; color: var(--tieu-de); }
.cam-ket__muc span { font-size: 14px; color: var(--chu-2); }
@media (max-width: 860px) { .mo-dau { grid-template-columns: 1fr; gap: 18px; } }

.bo-loc { display: flex; flex-wrap: wrap; gap: 10px; align-items: end; padding: 14px; background: var(--mat); border-radius: var(--r); border: .5px solid var(--vien);
  position: sticky; top: 58px; z-index: 10; box-shadow: var(--bong); }
.bo-loc label { display: grid; gap: 4px; font-size: 13px; font-weight: 700; color: var(--chu-3); flex: 1 1 160px; }
.bo-loc select { min-height: 40px; border-radius: 10px; border: 1.5px solid var(--vien-dam); background: var(--mat); padding: 0 10px; font-weight: 600; color: var(--chu); }
.dem-kq { margin: 18px 4px 10px; font-weight: 700; color: var(--chu-2); }

/* ---------- thẻ gia sư trong danh sách ---------- */
.ds-gia-su { display: grid; gap: 16px; }
.the-gs { display: grid; grid-template-columns: 132px 1fr 220px; gap: 20px; padding: 20px; background: var(--mat); border-radius: var(--r);
  border: .5px solid var(--vien); box-shadow: var(--bong); }
.the-gs__anh { width: 132px; height: 132px; border-radius: 16px; object-fit: cover; display: block; background: var(--sm-oai); }
.the-gs__ten { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.the-gs__ten h3 { font-size: 22px; }
.the-gs__ten a { color: inherit; }
.the-gs__tieu-de { font-weight: 700; color: var(--chu); margin: 4px 0 8px; }
.the-gs__mo-ta { color: var(--chu-2); font-size: 15px; margin: 10px 0 0; display: -webkit-box; -webkit-line-clamp: 3; -webkit-box-orient: vertical; overflow: hidden; }
.the-gs__so { display: flex; gap: 18px; margin-top: 10px; font-size: 14px; color: var(--chu-2); }
.the-gs__so b { color: var(--tieu-de); font-family: var(--chu-de); font-weight: 400; font-size: 17px; }
.the-gs__ben { display: flex; flex-direction: column; gap: 10px; }
.gia { font: 400 26px var(--chu-de); color: var(--tieu-de); line-height: 1; }
.gia small { font: 600 13px var(--chu-than); color: var(--chu-3); display: block; margin-top: 4px; }
@media (max-width: 860px) {
  .the-gs { grid-template-columns: 88px 1fr; }
  .the-gs__anh { width: 88px; height: 88px; }
  .the-gs__ben { grid-column: 1 / -1; flex-direction: row; flex-wrap: wrap; align-items: center; }
  .the-gs__ben .gia { flex-basis: 100%; }
  .the-gs__ben .nut { flex: 1 1 0; }
}

.anh-chu { display: grid; place-items: center; color: #fff; font: 400 40px var(--chu-de);
  background: linear-gradient(135deg, var(--sm-hong), var(--sm-khoi)); }

/* ---------- hồ sơ gia sư ---------- */
.ho-so { display: grid; grid-template-columns: 1fr 340px; gap: 28px; align-items: start; }
.ho-so__dau { display: flex; gap: 20px; align-items: center; }
.ho-so__anh { width: 128px; height: 128px; border-radius: 20px; object-fit: cover; flex: none; }
.ho-so section { margin-top: 28px; }
.ho-so section h2 { margin-bottom: 10px; }
.van-ban { white-space: pre-line; color: var(--chu); }
.ben-dinh { position: sticky; top: 76px; display: grid; gap: 14px; }
.video { position: relative; aspect-ratio: 16 / 9; border-radius: var(--r); overflow: hidden; background: #000; }
.video iframe { position: absolute; inset: 0; width: 100%; height: 100%; border: 0; }
@media (max-width: 920px) { .ho-so { grid-template-columns: 1fr; } .ben-dinh { position: static; } .ho-so__anh { width: 96px; height: 96px; } }

/* lịch giờ trống kiểu Preply: 7 cột ngày, mỗi giờ một nút */
.lich__dieu-khien { display: flex; align-items: center; gap: 8px; margin-bottom: 12px; }
.lich__dieu-khien b { margin-right: auto; }
.lich { display: grid; grid-template-columns: repeat(7, minmax(0, 1fr)); gap: 6px; }
.lich__cot { display: grid; gap: 6px; align-content: start; }
.lich__ngay { text-align: center; padding: 6px 0 8px; border-bottom: 2px solid var(--vien); margin-bottom: 4px; }
.lich__ngay b { display: block; font: 400 15px var(--chu-de); color: var(--tieu-de); }
.lich__ngay span { font-size: 12px; color: var(--chu-3); }
.o-gio { border: 1.5px solid var(--vien-dam); background: var(--mat); border-radius: 9px; padding: 6px 0; font-weight: 700; font-size: 14px; cursor: pointer; color: var(--chu); }
.o-gio:hover { border-color: var(--nhan); color: var(--nhan); }
.o-gio.chon { background: var(--sm-khoi); color: #fff; border-color: var(--sm-khoi); }
.lich__trong { font-size: 12px; text-align: center; color: var(--chu-3); padding: 8px 0; }
@media (max-width: 600px) { .lich { grid-template-columns: repeat(7, 74px); overflow-x: auto; padding-bottom: 6px; } }

/* ---------- hộp thoại ---------- */
dialog.hop { border: 0; padding: 0; border-radius: 22px; width: min(520px, calc(100vw - 32px)); background: var(--mat); color: var(--chu);
  box-shadow: 0 24px 80px rgba(20, 0, 60, .35); }
dialog.hop::backdrop { background: rgba(20, 8, 50, .45); -webkit-backdrop-filter: blur(4px); backdrop-filter: blur(4px); }
.hop__than { padding: 24px; max-height: calc(100vh - 80px); overflow: auto; }
.hop__than h2 { margin-bottom: 6px; }
.hop__nut { display: flex; gap: 10px; justify-content: flex-end; margin-top: 20px; flex-wrap: wrap; }
.cong-ph__q { font: 400 40px var(--chu-de); color: var(--tieu-de); text-align: center; margin: 16px 0 10px; }
.cong-ph input { text-align: center; font: 400 28px var(--chu-de); }
.thong-bao-loi { color: var(--loi); font-weight: 700; min-height: 1.4em; margin: 8px 0 0; }

/* ---------- thanh toán ---------- */
.tt { display: grid; grid-template-columns: 300px 1fr; gap: 28px; align-items: start; max-width: 860px; margin: 0 auto; }
.tt__qr { width: 100%; border-radius: 16px; background: #fff; display: block; aspect-ratio: 1 / 1.1; object-fit: contain; }
.dong { display: flex; justify-content: space-between; gap: 12px; padding: 10px 0; border-bottom: .5px solid var(--vien); }
.dong:last-child { border-bottom: 0; }
.dong span { color: var(--chu-3); }
.dong b { text-align: right; }
.nut-chep { border: 0; background: var(--nhan-nhat); color: var(--nhan); border-radius: 8px; padding: 2px 8px; margin-left: 6px; cursor: pointer; font-weight: 700; font-size: 13px; }
@media (max-width: 760px) { .tt { grid-template-columns: 1fr; } .tt__qr { max-width: 320px; margin: 0 auto; } }

/* ---------- danh sách buổi học ---------- */
.ds-buoi { display: grid; gap: 12px; }
.buoi { display: grid; grid-template-columns: 76px 1fr auto; gap: 16px; align-items: center; padding: 16px; background: var(--mat); border-radius: var(--r);
  border: .5px solid var(--vien); }
.buoi__ngay { text-align: center; background: var(--sm-oai); color: var(--sm-dem); border-radius: 14px; padding: 8px 4px; }
.buoi__ngay b { display: block; font: 400 26px var(--chu-de); line-height: 1; }
.buoi__ngay span { font-size: 12px; font-weight: 700; }
.buoi__tieu-de { font-weight: 700; }
.buoi__nut { display: flex; gap: 8px; flex-wrap: wrap; justify-content: flex-end; }
@media (max-width: 700px) { .buoi { grid-template-columns: 64px 1fr; } .buoi__nut { grid-column: 1 / -1; justify-content: flex-start; } }

.bang-trong { text-align: center; padding: 48px 16px; color: var(--chu-2); }
.bang-trong h2 { margin-bottom: 8px; }

.loading { display: flex; justify-content: center; padding: 60px; }
.loading::after { content: ""; width: 26px; height: 26px; border-radius: 50%; border: 3px solid var(--nhan-nhat); border-top-color: var(--nhan); animation: quay .8s linear infinite; }
@keyframes quay { to { transform: rotate(360deg); } }

.toast { position: fixed; left: 50%; bottom: 24px; transform: translate(-50%, 20px); opacity: 0; background: var(--sm-dem); color: #fff; padding: 12px 18px;
  border-radius: 14px; font-weight: 700; z-index: 100; transition: .25s; pointer-events: none; max-width: calc(100vw - 32px); }
.toast.hien { opacity: 1; transform: translate(-50%, 0); }

/* ---------- khu làm việc gia sư / vận hành (kiểu Apple như quan-tri.css) ---------- */
.khu { display: grid; grid-template-columns: 220px 1fr; gap: 24px; align-items: start; }
.khu__ben { position: sticky; top: 76px; display: grid; gap: 2px; }
.khu__ben button { text-align: left; border: 0; background: none; padding: 9px 12px; border-radius: 10px; font-weight: 700; color: var(--chu-2); cursor: pointer;
  display: flex; justify-content: space-between; align-items: center; }
.khu__ben button:hover { background: var(--nhan-nhat); }
.khu__ben button.dang-o { background: var(--sm-khoi); color: #fff; }
.khu__ben .dem { font-size: 12px; background: var(--cta); color: #fff; border-radius: 999px; padding: 1px 8px; }
.khu__noi h1 { font-size: 30px; margin-bottom: 18px; }
@media (max-width: 800px) {
  .khu { grid-template-columns: 1fr; }
  .khu__ben { position: static; display: flex; overflow-x: auto; gap: 6px; }
  .khu__ben button { white-space: nowrap; }
}
.luoi-so { display: grid; grid-template-columns: repeat(auto-fill, minmax(180px, 1fr)); gap: 12px; margin-bottom: 20px; }
.o-so { background: var(--mat); border: .5px solid var(--vien); border-radius: var(--r-sm); padding: 14px 16px; }
.o-so span { font-size: 13px; color: var(--chu-3); font-weight: 700; }
.o-so b { display: block; font: 400 28px var(--chu-de); color: var(--tieu-de); }
.bang { width: 100%; border-collapse: collapse; background: var(--mat); border-radius: var(--r-sm); overflow: hidden; border: .5px solid var(--vien); font-size: 14px; }
.bang th, .bang td { padding: 10px 12px; text-align: left; border-bottom: .5px solid var(--vien); vertical-align: top; }
.bang th { font-size: 12px; color: var(--chu-3); background: var(--mat-2); }
.bang tr:last-child td { border-bottom: 0; }
.bang .so { text-align: right; font-variant-numeric: tabular-nums; white-space: nowrap; }
.cuon-ngang { overflow-x: auto; }
.hang-gio { display: grid; grid-template-columns: 110px 1fr; gap: 12px; align-items: start; padding: 12px 0; border-bottom: .5px solid var(--vien); }
.hang-gio__khung { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; }
.khung { display: inline-flex; align-items: center; gap: 6px; background: var(--mat-2); border: 1px solid var(--vien); border-radius: 10px; padding: 4px 6px; }
.khung input { width: 96px; border: 0; background: transparent; font-weight: 700; }
.khung button { border: 0; background: none; cursor: pointer; color: var(--chu-3); font-size: 18px; line-height: 1; }
.luoi-form { display: grid; grid-template-columns: 1fr 1fr; gap: 0 16px; }
@media (max-width: 700px) { .luoi-form { grid-template-columns: 1fr; } .hang-gio { grid-template-columns: 1fr; } }
.chon-chip { display: flex; flex-wrap: wrap; gap: 8px; }
.chon-chip label { display: inline-flex; gap: 6px; align-items: center; border: 1.5px solid var(--vien-dam); border-radius: 999px; padding: 4px 12px; cursor: pointer; font-weight: 700; font-size: 14px; }
.chon-chip input { accent-color: var(--sm-khoi); }
.chan { text-align: center; color: var(--chu-3); font-size: 13px; padding: 28px 16px 40px; }

/* ---------- điện thoại ---------- */
.dau__nhan { white-space: nowrap; }
.cam-ket__muc span, .goi-y, .phu, .the-gs__mo-ta { text-wrap: pretty; }
.cam-ket__muc span { display: block; }
@media (max-width: 700px) {
  .dau__trong { flex-wrap: wrap; gap: 6px 10px; padding: 8px 16px 6px; }
  .dau__menu { margin-left: 0; width: 100%; flex-wrap: nowrap; justify-content: flex-start; overflow-x: auto; scrollbar-width: none; }
  .dau__menu a { padding: 6px 10px; font-size: 14px; white-space: nowrap; }
  .dau__menu a:last-child { margin-left: auto; }
  .bo-loc { position: static; }
  .bo-loc label { flex: 1 1 140px; }
  main { padding-top: 16px; }
}