.tutor-app {
    --bg: #f4f7fb;
    --panel: #ffffff;
    --text: #172033;
    --muted: #637083;
    --primary: #2457d6;
    --primary-dark: #1c45ab;
    --secondary: #eef3ff;
    --border: #dbe4f0;
    --shadow: 0 18px 55px rgba(20, 34, 66, .10);
    --radius: 22px;
    font-family: Arial, Helvetica, sans-serif;
    color: var(--text);
    line-height: 1.55;
    background:
        radial-gradient(circle at top left, rgba(36, 87, 214, .12), transparent 32rem),
        linear-gradient(180deg, #fbfdff 0%, var(--bg) 100%);
    padding: 1px 0;
}

.tutor-app * { box-sizing: border-box; }

.tutor-wrap {
    width: min(1160px, calc(100% - 32px));
    margin: 0 auto;
}

.tutor-internal-header {
    position: sticky;
    top: 0;
    z-index: 20;
    background: rgba(255,255,255,.88);
    border-bottom: 1px solid var(--border);
    backdrop-filter: blur(14px);
}

.tutor-app .header-inner {
    min-height: 72px;
    display: flex;
    align-items: center;
    gap: 18px;
    justify-content: space-between;
}

.tutor-app .brand {
    display: inline-flex;
    align-items: center;
    gap: 12px;
    text-decoration: none;
    color: var(--text);
    white-space: nowrap;
}

.tutor-app .brand-mark {
    width: 44px;
    height: 44px;
    display: grid;
    place-items: center;
    border-radius: 14px;
    background: var(--primary);
    color: #fff;
    font-weight: 800;
    letter-spacing: .03em;
}

.tutor-app .brand small {
    display: block;
    color: var(--muted);
    margin-top: -2px;
}

.tutor-app .nav {
    display: flex;
    align-items: center;
    gap: 8px;
    flex-wrap: wrap;
    justify-content: flex-end;
}

.tutor-app .nav a,
.tutor-app .logout {
    text-decoration: none;
    color: var(--muted);
    padding: 8px 10px;
    border-radius: 999px;
    font-size: 14px;
}

.tutor-app .nav a:hover,
.tutor-app .logout:hover {
    color: var(--primary);
    background: var(--secondary);
}

.tutor-main { padding: 34px 0 60px; }

.tutor-app .page-title { margin-bottom: 24px; }
.tutor-app .page-title h1 { margin: 0 0 8px; font-size: clamp(32px, 5vw, 54px); letter-spacing: -.04em; line-height: 1; }
.tutor-app .page-title p { margin: 0; color: var(--muted); font-size: 18px; max-width: 780px; }

.tutor-app .panel {
    background: rgba(255,255,255,.94);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: clamp(18px, 3vw, 30px);
    margin-bottom: 24px;
}

.tutor-app .hero-home {
    display: grid;
    grid-template-columns: minmax(0, 1.45fr) minmax(260px, .9fr);
    gap: 24px;
    align-items: center;
    overflow: hidden;
}

.tutor-app .eyebrow {
    color: var(--primary);
    font-weight: 800;
    text-transform: uppercase;
    letter-spacing: .09em;
    font-size: 13px;
    margin: 0 0 12px;
}

.tutor-app .hero-copy h2 {
    font-size: clamp(28px, 4vw, 48px);
    line-height: 1.03;
    letter-spacing: -.035em;
    margin: 0 0 14px;
}

.tutor-app .hero-copy p { color: var(--muted); font-size: 18px; max-width: 760px; }
.tutor-app .hero-actions { display: flex; gap: 12px; flex-wrap: wrap; margin-top: 22px; }

.tutor-app .hero-canvas-card {
    position: relative;
    min-height: 300px;
    border-radius: 28px;
    overflow: hidden;
    border: 1px solid rgba(36,87,214,.18);
    background: linear-gradient(145deg, #eef3ff, #fff7db, #ecfff5);
    box-shadow: 0 18px 48px rgba(20,34,66,.11);
}

.tutor-app #tutorHeroCanvas {
    display: block;
    width: 100%;
    height: 300px;
}

.tutor-app .canvas-overlay {
    position: absolute;
    left: 18px;
    right: 18px;
    bottom: 18px;
    background: rgba(255,255,255,.76);
    border: 1px solid rgba(255,255,255,.8);
    backdrop-filter: blur(12px);
    border-radius: 20px;
    padding: 16px;
    box-shadow: 0 12px 32px rgba(20,34,66,.10);
}

.tutor-app .canvas-overlay strong { display: block; font-size: 24px; line-height: 1.05; }
.tutor-app .canvas-overlay span { display: block; color: var(--muted); margin-top: 4px; }
.tutor-app .canvas-overlay em { display: block; color: var(--primary); font-style: normal; font-weight: 800; margin-top: 7px; }

.tutor-app .subjects-section { margin: 32px 0 26px; }
.tutor-app .subjects-section h2 { margin: 0 0 16px; }
.tutor-app .subjects-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 16px;
}

.tutor-app .subject-card {
    background: #fff;
    border: 1px solid var(--border);
    border-radius: 20px;
    padding: 20px;
    min-height: 175px;
    text-decoration: none;
    color: var(--text);
    box-shadow: 0 10px 28px rgba(20,34,66,.07);
    display: flex;
    flex-direction: column;
    gap: 10px;
    transition: transform .18s ease, box-shadow .18s ease, border-color .18s ease;
}
.tutor-app .subject-card:hover { transform: translateY(-3px); box-shadow: var(--shadow); border-color: rgba(36,87,214,.36); }
.tutor-app .subject-icon { font-size: 34px; }
.tutor-app .subject-card strong { font-size: 20px; }
.tutor-app .subject-card small { color: var(--muted); font-size: 14px; }

.tutor-app .features-grid {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 14px;
}
.tutor-app .features-grid div {
    background: #f8fbff;
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 16px;
}
.tutor-app .features-grid strong { display: block; margin-bottom: 4px; }
.tutor-app .features-grid span { color: var(--muted); font-size: 14px; }

.tutor-app .tool-layout {
    display: grid;
    grid-template-columns: minmax(0, 1fr) 330px;
    gap: 22px;
    align-items: start;
}

.tutor-app .panel-heading {
    display: flex;
    align-items: flex-start;
    gap: 14px;
    margin-bottom: 22px;
}
.tutor-app .big-icon {
    width: 58px;
    height: 58px;
    border-radius: 18px;
    display: grid;
    place-items: center;
    background: var(--secondary);
    font-size: 28px;
    flex: 0 0 auto;
}
.tutor-app .panel-heading h2 { margin: 0 0 3px; }
.tutor-app .panel-heading p { margin: 0; color: var(--muted); }

.tutor-app .grid.two {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 16px;
}

.tutor-app .field { margin-bottom: 16px; }
.tutor-app label { display: block; font-weight: 800; margin-bottom: 7px; }
.tutor-app input[type="text"],
.tutor-app input[type="password"],
.tutor-app input[type="file"],
.tutor-app select,
.tutor-app textarea {
    width: 100%;
    border: 1px solid var(--border);
    border-radius: 14px;
    padding: 13px 14px;
    font: inherit;
    background: #fff;
    color: var(--text);
}
.tutor-app textarea { resize: vertical; min-height: 120px; }
.tutor-app small, .tutor-app .muted { color: var(--muted); }

.tutor-app .actions { display: flex; gap: 12px; flex-wrap: wrap; }
.tutor-app .btn {
    border: 0;
    border-radius: 14px;
    padding: 12px 18px;
    font-weight: 800;
    text-decoration: none;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}
.tutor-app .btn.primary { background: var(--primary); color: #fff; }
.tutor-app .btn.primary:hover { background: var(--primary-dark); }
.tutor-app .btn.secondary { background: var(--secondary); color: var(--primary); }
.tutor-app .btn.ghost { background: #f8fbff; color: var(--muted); border: 1px solid var(--border); }
.tutor-app .btn.full { width: 100%; margin-top: 14px; }
.tutor-app .btn:disabled { opacity: .55; cursor: not-allowed; }

.tutor-app .help-panel { position: sticky; top: 96px; }
.tutor-app .method-list { padding-left: 22px; color: var(--muted); }
.tutor-app .method-list li { margin: 8px 0; }
.tutor-app .symbols-table-wrap { overflow-x: auto; }
.tutor-app .symbols-table { width: 100%; border-collapse: collapse; font-size: 14px; }
.tutor-app .symbols-table td { border-bottom: 1px solid var(--border); padding: 8px 6px; }
.tutor-app .symbols-table td:first-child { font-weight: 800; color: var(--primary); white-space: nowrap; }

.tutor-app .result-panel { margin-top: 24px; }
.tutor-app .result-toolbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 12px;
    border-bottom: 1px solid var(--border);
    padding-bottom: 14px;
    margin-bottom: 18px;
}
.tutor-app .result-toolbar h2 { margin: 0; }
.tutor-app .status-box {
    background: #f8fbff;
    border: 1px solid var(--border);
    color: var(--muted);
    border-radius: 14px;
    padding: 13px 14px;
    margin-bottom: 16px;
}
.tutor-app .status-box.loading { color: var(--primary); }
.tutor-app .status-box.error { color: #b42318; background: #fff4f2; border-color: #ffd5cf; }
.tutor-app .answer-content h2 { font-size: 30px; margin: 0 0 12px; }
.tutor-app .answer-section { margin: 22px 0; }
.tutor-app .answer-section h3 {
    margin: 0 0 10px;
    color: var(--primary);
    border-bottom: 1px solid var(--border);
    padding-bottom: 7px;
}
.tutor-app .answer-list { margin: 0; padding-left: 22px; }
.tutor-app .answer-list li { margin: 7px 0; }
.tutor-app .keyword-table { width: 100%; border-collapse: collapse; }
.tutor-app .keyword-table th,
.tutor-app .keyword-table td { text-align: left; border-bottom: 1px solid var(--border); padding: 10px; vertical-align: top; }
.tutor-app .keyword-table th { color: var(--muted); font-size: 13px; text-transform: uppercase; letter-spacing: .05em; }
.tutor-app .step-card,
.tutor-app .exercise-card {
    background: #fbfdff;
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 16px;
    margin: 12px 0;
}
.tutor-app .step-card h4,
.tutor-app .exercise-card h4 { margin: 0 0 8px; }
.tutor-app .final-box {
    background: linear-gradient(145deg, #eef3ff, #ffffff);
    border: 1px solid rgba(36,87,214,.24);
    border-radius: 18px;
    padding: 18px;
    font-weight: 700;
}

.tutor-app .login-page { min-height: 100vh; display: grid; place-items: center; padding: 24px; }
.tutor-app .login-box { width: min(420px, 100%); background: #fff; border: 1px solid var(--border); border-radius: var(--radius); box-shadow: var(--shadow); padding: 28px; }
.tutor-app .alert.error { background: #fff4f2; color: #b42318; border: 1px solid #ffd5cf; padding: 12px; border-radius: 14px; margin-bottom: 14px; }

.tutor-internal-footer { border-top: 1px solid var(--border); color: var(--muted); padding: 24px 0; background: rgba(255,255,255,.72); }

.tutor-app .limit-box {
    background: #fff8e6;
    border: 1px solid #f2d38b;
    color: #705000;
    border-radius: 14px;
    padding: 12px 14px;
    margin-bottom: 16px;
    font-weight: 700;
}

.tutor-app .ad-slot { display: none; }

@media (max-width: 940px) {
    .tutor-app .header-inner { align-items: flex-start; flex-direction: column; padding: 14px 0; }
    .tutor-app .nav { justify-content: flex-start; }
    .tutor-app .hero-home, .tutor-app .tool-layout { grid-template-columns: 1fr; }
    .tutor-app .help-panel { position: static; }
    .tutor-app .subjects-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .tutor-app .features-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 640px) {
    .tutor-wrap { width: min(100% - 24px, 1160px); }
    .tutor-app .grid.two, .tutor-app .subjects-grid, .tutor-app .features-grid { grid-template-columns: 1fr; }
    .tutor-app .result-toolbar { align-items: flex-start; flex-direction: column; }
    .tutor-app .btn { width: 100%; }
}

@media print {
    body { background: #fff !important; }
    .site-header, .site-footer, .tutor-internal-header, .tutor-internal-footer, .page-title, .tool-layout, .result-toolbar, .status-box, .limit-box { display: none !important; }
    .tutor-app { background: #fff !important; padding: 0 !important; }
    .tutor-wrap { width: 100% !important; }
    .tutor-main { padding: 0 !important; }
    .tutor-app .panel { box-shadow: none !important; border: 0 !important; padding: 0 !important; margin: 0 !important; }
    .tutor-app .result-panel { display: block !important; }
    #printArea { display: block !important; color: #000 !important; }
    .tutor-app .answer-section { break-inside: avoid; }
}