/* AI Homework Assistant - Public CSS
 * Responsive, mobile-first, light + dark via CSS variables.
 */

:root {
    --aiha-bg:        #f7f7f4;
    --aiha-surface:   #ffffff;
    --aiha-surface-2: #f1efe9;
    --aiha-border:    #e6e3da;
    --aiha-text:      #1c1b1a;
    --aiha-muted:     #6f6c63;
    --aiha-primary:   #d8542f;
    --aiha-primary-2: #b3401e;
    --aiha-accent:    #2a6f6f;
    --aiha-success:   #2e7d32;
    --aiha-danger:    #c0392b;
    --aiha-radius:    14px;
    --aiha-shadow:    0 1px 2px rgba(0,0,0,.04), 0 8px 24px rgba(20,18,15,.06);
    --aiha-font:      "Fraunces", "Iowan Old Style", "Georgia", "DejaVu Serif", serif;
    --aiha-font-ui:   "IBM Plex Sans", "Inter", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

@media (prefers-color-scheme: dark) {
    body.aiha-theme-auto {
        --aiha-bg:        #14130f;
        --aiha-surface:   #1c1b18;
        --aiha-surface-2: #232118;
        --aiha-border:    #2e2b22;
        --aiha-text:      #f3efe6;
        --aiha-muted:     #a59f8f;
        --aiha-primary:   #ff7a4a;
        --aiha-primary-2: #ff9468;
        --aiha-accent:    #4dc7c7;
        --aiha-shadow:    0 1px 2px rgba(0,0,0,.4), 0 12px 32px rgba(0,0,0,.5);
    }
}

body.aiha-theme-dark .aiha-app,
.aiha-app.is-dark {
    --aiha-bg:        #14130f;
    --aiha-surface:   #1c1b18;
    --aiha-surface-2: #232118;
    --aiha-border:    #2e2b22;
    --aiha-text:      #f3efe6;
    --aiha-muted:     #a59f8f;
    --aiha-primary:   #ff7a4a;
    --aiha-primary-2: #ff9468;
    --aiha-accent:    #4dc7c7;
}

.aiha-app {
    font-family: var(--aiha-font-ui);
    color: var(--aiha-text);
    background: var(--aiha-bg);
    border-radius: var(--aiha-radius);
    padding: clamp(16px, 3vw, 32px);
    max-width: 1100px;
    margin: 24px auto;
    box-shadow: var(--aiha-shadow);
}

.aiha-app .aiha-h {
    font-family: var(--aiha-font);
    font-size: clamp(1.5rem, 2.5vw, 2.25rem);
    font-weight: 500;
    letter-spacing: -0.01em;
    margin: 0 0 16px 0;
    color: var(--aiha-text);
}

.aiha-app .aiha-h-sm {
    font-family: var(--aiha-font);
    font-weight: 500;
    font-size: 1.1rem;
    margin: 16px 0 8px;
}

.aiha-app h3 { font-family: var(--aiha-font); font-weight: 500; margin: 0 0 8px; }
.aiha-app p { line-height: 1.55; }
.aiha-app .aiha-muted { color: var(--aiha-muted); font-size: 0.9rem; }

.aiha-toolbar {
    display: flex;
    align-items: center;
    gap: 16px;
    flex-wrap: wrap;
    margin-bottom: 20px;
}
.aiha-toolbar .aiha-h { flex: 1; margin: 0; }

.aiha-credits-badge {
    background: var(--aiha-surface-2);
    color: var(--aiha-text);
    padding: 6px 12px;
    border-radius: 999px;
    font-size: 0.85rem;
    border: 1px solid var(--aiha-border);
}

.aiha-theme-toggle {
    background: transparent;
    border: 1px solid var(--aiha-border);
    border-radius: 999px;
    width: 36px;
    height: 36px;
    cursor: pointer;
    color: var(--aiha-text);
    transition: background .2s;
}
.aiha-theme-toggle:hover { background: var(--aiha-surface-2); }

/* Card */
.aiha-card {
    background: var(--aiha-surface);
    border: 1px solid var(--aiha-border);
    border-radius: var(--aiha-radius);
    padding: 20px;
    margin: 16px 0;
}

.aiha-grid-2 { display: grid; gap: 16px; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); }
.aiha-grid-3 { display: grid; gap: 16px; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); margin: 12px 0; }

.aiha-stat-card {
    background: var(--aiha-surface);
    border: 1px solid var(--aiha-border);
    border-radius: var(--aiha-radius);
    padding: 16px;
    display: flex;
    flex-direction: column;
}
.aiha-stat-label { color: var(--aiha-muted); font-size: 0.85rem; }
.aiha-stat-value { font-family: var(--aiha-font); font-size: 1.8rem; font-weight: 500; }

/* Auth */
.aiha-auth-card {
    background: var(--aiha-surface);
    border: 1px solid var(--aiha-border);
    border-radius: var(--aiha-radius);
    padding: 24px;
    max-width: 460px;
    margin: 0 auto;
}
.aiha-auth-tabs {
    display: flex;
    gap: 4px;
    margin-bottom: 16px;
    background: var(--aiha-surface-2);
    padding: 4px;
    border-radius: 999px;
}
.aiha-tab {
    flex: 1;
    padding: 8px 12px;
    border: 0;
    background: transparent;
    color: var(--aiha-muted);
    border-radius: 999px;
    cursor: pointer;
    font-weight: 600;
    transition: background .2s, color .2s;
}
.aiha-tab.is-active { background: var(--aiha-surface); color: var(--aiha-text); box-shadow: var(--aiha-shadow); }

.aiha-form { display: flex; flex-direction: column; gap: 12px; }
.aiha-form label { display: flex; flex-direction: column; gap: 6px; font-size: 0.9rem; color: var(--aiha-muted); }
.aiha-form input, .aiha-form select, .aiha-field input, .aiha-field select {
    padding: 10px 12px;
    border-radius: 10px;
    border: 1px solid var(--aiha-border);
    background: var(--aiha-surface-2);
    color: var(--aiha-text);
    font: inherit;
    transition: border-color .2s;
}
.aiha-form input:focus, .aiha-form select:focus, .aiha-field input:focus, .aiha-field select:focus {
    outline: none;
    border-color: var(--aiha-primary);
}
.aiha-form-error { color: var(--aiha-danger); font-size: 0.9rem; min-height: 1em; }

/* Buttons */
.aiha-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 10px 18px;
    border-radius: 999px;
    border: 1px solid var(--aiha-border);
    background: var(--aiha-surface);
    color: var(--aiha-text);
    font-weight: 600;
    cursor: pointer;
    transition: background .2s, transform .12s, border-color .2s;
    font: 600 0.95rem var(--aiha-font-ui);
}
.aiha-btn:hover { background: var(--aiha-surface-2); transform: translateY(-1px); }
.aiha-btn:active { transform: translateY(0); }
.aiha-btn-primary { background: var(--aiha-primary); color: #fff; border-color: var(--aiha-primary); }
.aiha-btn-primary:hover { background: var(--aiha-primary-2); border-color: var(--aiha-primary-2); }
.aiha-btn-lg { padding: 14px 22px; font-size: 1rem; }
.aiha-btn-ghost { background: transparent; }

/* Dropzone */
.aiha-dropzone {
    position: relative;
    border: 2px dashed var(--aiha-border);
    border-radius: var(--aiha-radius);
    padding: 32px;
    text-align: center;
    background: var(--aiha-surface-2);
    transition: border-color .2s, background .2s;
    cursor: pointer;
    overflow: hidden;
}
.aiha-dropzone.is-drag { border-color: var(--aiha-primary); background: color-mix(in srgb, var(--aiha-primary) 8%, var(--aiha-surface-2)); }
.aiha-dropzone input[type="file"] {
    position: absolute; inset: 0; opacity: 0; cursor: pointer;
}
.aiha-dropzone-inner { display: flex; flex-direction: column; gap: 6px; color: var(--aiha-muted); }
.aiha-dropzone-inner strong { color: var(--aiha-text); font-family: var(--aiha-font); font-size: 1.1rem; }
.aiha-preview { max-width: 100%; max-height: 220px; border-radius: 10px; margin-top: 12px; display: none; }
.aiha-preview.is-on { display: inline-block; }

.aiha-row { display: flex; flex-wrap: wrap; gap: 12px; margin: 16px 0; }
.aiha-field { display: flex; flex-direction: column; gap: 6px; flex: 1 1 140px; font-size: 0.9rem; color: var(--aiha-muted); }
.aiha-field-block { display: block; margin: 12px 0; }
.aiha-field textarea {
    width: 100%;
    min-height: 140px;
    padding: 12px 14px;
    border-radius: 10px;
    border: 1px solid var(--aiha-border);
    background: var(--aiha-surface-2);
    color: var(--aiha-text);
    font: inherit;
    resize: vertical;
    transition: border-color .2s;
}
.aiha-field textarea:focus { outline: none; border-color: var(--aiha-primary); }

/* Mode tabs */
.aiha-mode-tabs {
    display: flex;
    gap: 4px;
    margin-bottom: 16px;
    background: var(--aiha-surface-2);
    padding: 4px;
    border-radius: 14px;
    flex-wrap: wrap;
}
.aiha-mode-tab {
    flex: 1 1 110px;
    padding: 10px 14px;
    border: 0;
    background: transparent;
    color: var(--aiha-muted);
    border-radius: 10px;
    cursor: pointer;
    font: 600 0.92rem var(--aiha-font-ui);
    transition: background .2s, color .2s, transform .12s;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}
.aiha-mode-tab span[aria-hidden] { font-size: 1.05em; color: var(--aiha-primary); }
.aiha-mode-tab:hover { color: var(--aiha-text); }
.aiha-mode-tab.is-active {
    background: var(--aiha-surface);
    color: var(--aiha-text);
    box-shadow: var(--aiha-shadow);
}

/* Camera */
.aiha-camera {
    position: relative;
    background: var(--aiha-surface-2);
    border: 1px solid var(--aiha-border);
    border-radius: var(--aiha-radius);
    padding: 16px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
}
.aiha-camera-video {
    width: 100%;
    max-height: 320px;
    border-radius: 10px;
    background: #000;
    display: none;
    object-fit: cover;
}
.aiha-camera-video.is-on { display: block; }
.aiha-camera-controls { display: flex; gap: 10px; flex-wrap: wrap; justify-content: center; }
.aiha-camera-hint { margin: 0; }
.aiha-camera-fallback {
    position: absolute;
    width: 1px; height: 1px;
    opacity: 0;
    pointer-events: none;
}

/* Progress */
.aiha-progress { list-style: none; padding: 0; margin: 0; display: flex; flex-direction: column; gap: 12px; }
.aiha-progress li { display: flex; align-items: center; gap: 10px; color: var(--aiha-muted); }
.aiha-progress li.is-active { color: var(--aiha-text); }
.aiha-progress li.is-done { color: var(--aiha-success); }
.aiha-dot {
    width: 10px; height: 10px; border-radius: 999px;
    background: var(--aiha-border);
    transition: background .2s;
}
.aiha-progress li.is-active .aiha-dot { background: var(--aiha-primary); animation: aiha-pulse 1.2s ease-in-out infinite; }
.aiha-progress li.is-done .aiha-dot { background: var(--aiha-success); }
@keyframes aiha-pulse { 0%,100% { transform: scale(1); } 50% { transform: scale(1.4); } }

/* Steps */
.aiha-steps { padding-left: 20px; display: flex; flex-direction: column; gap: 10px; }
.aiha-steps li { color: var(--aiha-text); }
.aiha-steps li strong { display: block; font-family: var(--aiha-font); font-weight: 500; margin-bottom: 4px; }
.aiha-final { font-family: var(--aiha-font); font-size: 1.15rem; color: var(--aiha-text); padding: 12px; background: var(--aiha-surface-2); border-radius: 10px; border-left: 3px solid var(--aiha-primary); }

/* History */
.aiha-history { list-style: none; padding: 0; margin: 0; display: flex; flex-direction: column; gap: 8px; }
.aiha-history li {
    display: flex; align-items: center; gap: 12px;
    padding: 12px; border: 1px solid var(--aiha-border); border-radius: 10px;
    background: var(--aiha-surface-2); cursor: pointer; transition: background .2s;
}
.aiha-history li:hover { background: color-mix(in srgb, var(--aiha-primary) 6%, var(--aiha-surface-2)); }
.aiha-history li .aiha-q { flex: 1; }
.aiha-history li .aiha-st { font-size: 0.8rem; color: var(--aiha-muted); }

.is-hidden { display: none !important; }

/* Worksheet output */
.aiha-worksheet-out { margin-top: 12px; }
.aiha-worksheet-out ol { padding-left: 20px; display: flex; flex-direction: column; gap: 8px; }
.aiha-worksheet-out li strong { display: block; font-family: var(--aiha-font); }

/* Video slot */
[data-aiha-video-slot] video, [data-aiha-video-slot] audio { width: 100%; border-radius: 10px; margin-bottom: 8px; }

@media (max-width: 600px) {
    .aiha-toolbar { gap: 8px; }
    .aiha-h { font-size: 1.3rem; }
    .aiha-app { padding: 16px; margin: 12px; }
}