:root { --text: #172033; --heading: #172033; --muted: #64748b; --page: #eef3f8; --surface: rgba(255,255,255,.94); --field: #fbfdff; --border: #dce5f0; --field-border: #c9d5e5; --secondary: #edf2f8; --secondary-text: #34445f; --accent: #3767c7; --accent-hover: #2e58ad; --button-text: #fff; --notice: #edf4ff; --notice-text: #2857a9; font-family: Inter, ui-sans-serif, system-ui, -apple-system, sans-serif; color: var(--text); background: var(--page); }
[data-theme="dark"] { --text: #d9e2f2; --heading: #b9c9df; --muted: #9eacc1; --page: #121824; --surface: rgba(27,36,52,.96); --field: #172131; --border: #344258; --field-border: #4a5a73; --secondary: #33435f; --secondary-text: #d0daea; --notice: #1d355b; --notice-text: #b9cce8; --accent: #4b6da9; --accent-hover: #587cbb; --button-text: #dbe5f3; }
* { box-sizing: border-box; }
body { margin: 0; min-height: 100vh; background: radial-gradient(circle at 10% 0%, #dce9ff 0, transparent 34%), var(--page); transition: background .2s, color .2s; }
[data-theme="dark"] body { background: radial-gradient(circle at 10% 0%, #243554 0, transparent 34%), var(--page); }
.container { max-width: 760px; margin: 0 auto; padding: 56px 18px 72px; }
header { margin-bottom: 28px; position: relative; }
.theme-toggle { float: right; padding: 8px 11px; border: 1px solid var(--border); background: var(--secondary); color: var(--secondary-text); box-shadow: none; font-size: 12px; }
.theme-toggle:hover { background: var(--secondary); color: var(--secondary-text); }
.eyebrow { color: var(--accent); font-weight: 800; text-transform: uppercase; letter-spacing: .11em; font-size: 11px; }
h1 { margin: 9px 0 10px; font-size: clamp(28px, 5vw, 42px); line-height: 1.08; letter-spacing: -.04em; max-width: 680px; }
h1, h2, h3 { color: var(--heading); }
.muted, .hint { color: var(--muted); line-height: 1.55; }
.card { background: var(--surface); border: 1px solid var(--border); border-radius: 24px; padding: clamp(22px, 5vw, 34px); box-shadow: 0 24px 70px rgba(40, 68, 110, .12); }
h2 { margin: 0 0 8px; letter-spacing: -.025em; }
h3 { margin: 28px 0 4px; }
label { display: block; font-size: 14px; font-weight: 750; margin: 19px 0 8px; color: var(--secondary-text); }
input, select { width: 100%; border: 1px solid var(--field-border); border-radius: 12px; padding: 13px 14px; font: inherit; color: var(--text); background: var(--field); outline: none; transition: border-color .18s, box-shadow .18s; }
input:focus, select:focus { border-color: #4e78d6; box-shadow: 0 0 0 4px #4e78d620; }
.suggestion-field { position: relative; }
.suggestions { position: absolute; z-index: 5; top: calc(100% + 7px); left: 0; right: 0; display: none; padding: 7px; border: 1px solid var(--border); border-radius: 13px; background: var(--surface); box-shadow: 0 14px 32px rgba(35, 58, 95, .18); }
.suggestions.visible { display: grid; gap: 3px; }
.suggestion { width: 100%; padding: 10px 12px; border-radius: 9px; border: 0; background: transparent; color: var(--secondary-text); box-shadow: none; text-align: left; font-weight: 650; }
.suggestion:hover { background: var(--notice); color: var(--notice-text); transform: none; }
.check { display: flex; align-items: flex-start; gap: 10px; font-weight: 500; line-height: 1.45; }
.check input { appearance: none; width: 20px; height: 20px; flex: 0 0 auto; margin-top: 2px; border: 2px solid var(--field-border); border-radius: 4px; background: var(--field); cursor: pointer; }
.check input:checked { border-color: var(--accent); background-color: var(--accent); background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 20 20'%3E%3Cpath d='m4 10 4 4 8-8' fill='none' stroke='%23dbe5f3' stroke-width='2.5' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E"); background-position: center; background-repeat: no-repeat; background-size: 15px 15px; box-shadow: none; }
.check a { color: #3767c7; }
button { border: 0; border-radius: 12px; padding: 13px 17px; font: inherit; font-weight: 750; cursor: pointer; background: var(--accent); color: var(--button-text); box-shadow: 0 7px 16px #3767c733; transition: transform .15s, background .15s; }
button:hover { background: var(--accent-hover); transform: translateY(-1px); }
button.secondary { background: var(--secondary); color: var(--secondary-text); box-shadow: none; }
button.secondary:hover { background: var(--secondary); }
.actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 25px; }
.notice { padding: 14px 16px; border-radius: 12px; background: var(--notice); color: var(--notice-text); margin: 16px 0; line-height: 1.45; }
.form-error { display: none; }
.form-error.visible { display: block; }
.invalid { border-color: #c77735 !important; box-shadow: 0 0 0 4px #c7773520 !important; }
.warning { background: #fff0f3; color: #a13d55; }
.class-link { display: block; background: #f5f8fc; border: 1px solid #e4ebf4; padding: 15px 16px; border-radius: 13px; margin: 16px 0; word-break: break-all; }
[data-theme="dark"] .class-link { background: #202b3e; border-color: #3b4b65; }
[data-theme="dark"] .warning { background: #3e2633; color: #e7a6b6; }
.student { display: flex; justify-content: space-between; gap: 15px; align-items: center; padding: 15px 0; border-bottom: 1px solid #e8eef5; }
[data-theme="dark"] .student { border-bottom-color: #344258; }
.student:last-child { border-bottom: 0; }
.cancelled { opacity: .55; }
.teacher-actions { margin: 0 0 10px; }
.small { font-size: 13px; }
.modal-backdrop { position: fixed; inset: 0; z-index: 10; display: grid; place-items: center; padding: 18px; background: rgba(15, 23, 42, .52); backdrop-filter: blur(5px); }
.modal { width: min(100%, 480px); padding: 26px; border: 1px solid var(--border); border-radius: 20px; background: var(--surface); box-shadow: 0 24px 80px rgba(15, 23, 42, .28); }
.modal h2 { margin-bottom: 10px; }
.modal p { color: var(--muted); line-height: 1.5; }
.modal-input { margin-top: 8px; }
.modal-actions { justify-content: flex-end; }
@media (max-width: 520px) { .container { padding-top: 34px; } .card { border-radius: 18px; } .student { align-items: flex-start; flex-direction: column; gap: 8px; } .actions button { flex: 1 1 100%; } }