/* Curso de Alemán A1–B2 · Webapp · Estilos */

/* --- Variables --- */
:root {
    --c-primary: #0b3d91;
    --c-primary-light: #1a4ba0;
    --c-primary-bg: #eef2fa;
    --c-accent: #b5500c;
    --c-text: #1a1a1a;
    --c-text-soft: #555;
    --c-text-mute: #888;
    --c-bg: #ffffff;
    --c-bg-soft: #f7f7f9;
    --c-border: #e0e0e6;
    --c-success: #1d8048;
    --c-success-bg: #e6f4ec;
    --c-error: #b00020;
    --c-error-bg: #fdecef;
    --c-warn-bg: #fff7e6;
    --c-warn-border: #ffa940;
    --c-tip-bg: #fffbe6;
    --c-tip-border: #ffd666;
    --c-info-bg: #e6f1fb;
    --c-info-border: #4a90e2;
    
    --r-radius: 8px;
    --r-radius-sm: 4px;
    --r-radius-lg: 12px;
    
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
    --shadow-md: 0 2px 8px rgba(0,0,0,0.1);
    
    --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    --font-mono: "SF Mono", Menlo, Consolas, monospace;
}

/* --- Reset y base --- */
*, *::before, *::after { box-sizing: border-box; }

html { font-size: 16px; -webkit-text-size-adjust: 100%; }

body {
    margin: 0;
    font-family: var(--font);
    color: var(--c-text);
    background: var(--c-bg-soft);
    line-height: 1.5;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* --- Header --- */
.app-header {
    background: var(--c-bg);
    border-bottom: 1px solid var(--c-border);
    position: sticky;
    top: 0;
    z-index: 100;
}
.header-inner {
    max-width: 720px;
    margin: 0 auto;
    padding: 0.75rem 1rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
}
.brand {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
    color: var(--c-primary);
    font-weight: 600;
    font-size: 1.05rem;
}
.brand-icon { font-size: 1.3rem; }
.streak {
    font-size: 0.9rem;
    color: var(--c-text-mute);
}

/* --- Main --- */
.app-main {
    flex: 1;
    max-width: 720px;
    margin: 0 auto;
    padding: 1.25rem 1rem 5rem 1rem;
    width: 100%;
}
.loading {
    text-align: center;
    color: var(--c-text-mute);
    padding: 4rem 0;
}

/* --- Bottom nav --- */
.app-nav {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: var(--c-bg);
    border-top: 1px solid var(--c-border);
    display: flex;
    justify-content: space-around;
    z-index: 100;
    padding: 0.4rem 0;
}
.nav-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.15rem;
    text-decoration: none;
    color: var(--c-text-mute);
    padding: 0.3rem 0.5rem;
    font-size: 0.7rem;
    min-width: 60px;
}
.nav-item.active { color: var(--c-primary); }
.nav-icon { font-size: 1.2rem; }
.nav-label { font-size: 0.7rem; }

/* --- Botones --- */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.4rem;
    padding: 0.75rem 1.25rem;
    border-radius: var(--r-radius);
    border: none;
    font-family: inherit;
    font-size: 0.95rem;
    font-weight: 500;
    cursor: pointer;
    text-decoration: none;
    transition: background 0.15s, transform 0.05s;
    min-height: 44px;
}
.btn:active { transform: translateY(1px); }
.btn-primary {
    background: var(--c-primary);
    color: white;
}
.btn-primary:hover { background: var(--c-primary-light); }
.btn-primary:disabled { background: var(--c-text-mute); cursor: not-allowed; opacity: 0.6; }
.btn-secondary {
    background: var(--c-primary-bg);
    color: var(--c-primary);
}
.btn-ghost {
    background: transparent;
    color: var(--c-primary);
    padding: 0.5rem 1rem;
}
.btn-block { width: 100%; }
.btn-lg { font-size: 1.05rem; padding: 1rem 1.5rem; }

/* --- Cards --- */
.card {
    background: var(--c-bg);
    border-radius: var(--r-radius);
    padding: 1.25rem;
    box-shadow: var(--shadow-sm);
    margin-bottom: 1rem;
}

/* --- Home --- */
.hero {
    text-align: center;
    padding: 2rem 0 1.5rem 0;
}
.hero h1 {
    color: var(--c-primary);
    font-size: 1.75rem;
    margin: 0 0 0.5rem 0;
}
.hero p {
    color: var(--c-text-soft);
    margin: 0 0 1.5rem 0;
}

/* --- Niveles --- */
.level-list { display: grid; gap: 1rem; }
.level-card {
    display: block;
    padding: 1.25rem;
    background: var(--c-bg);
    border-radius: var(--r-radius);
    box-shadow: var(--shadow-sm);
    text-decoration: none;
    color: inherit;
    border-left: 4px solid var(--c-primary);
}
.level-card.locked {
    opacity: 0.5;
    cursor: not-allowed;
    border-left-color: var(--c-text-mute);
}
.level-card h3 {
    color: var(--c-primary);
    margin: 0 0 0.4rem 0;
    font-size: 1.2rem;
}
.level-card p {
    color: var(--c-text-soft);
    margin: 0 0 0.5rem 0;
    font-size: 0.9rem;
}
.level-meta {
    font-size: 0.8rem;
    color: var(--c-text-mute);
}

/* --- Unidades --- */
.unit-list { display: grid; gap: 0.75rem; margin-top: 1rem; }
.unit-card {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem;
    background: var(--c-bg);
    border-radius: var(--r-radius);
    box-shadow: var(--shadow-sm);
    text-decoration: none;
    color: inherit;
    border-left: 4px solid var(--c-border);
}
.unit-card.available { border-left-color: var(--c-primary); }
.unit-card.completed { border-left-color: var(--c-success); background: var(--c-success-bg); }
.unit-card.locked { opacity: 0.45; cursor: not-allowed; }
.unit-number {
    width: 2.5rem; height: 2.5rem;
    border-radius: 50%;
    background: var(--c-primary-bg);
    color: var(--c-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    flex-shrink: 0;
}
.unit-card.completed .unit-number { background: var(--c-success); color: white; }
.unit-info { flex: 1; min-width: 0; }
.unit-info h4 { margin: 0 0 0.2rem 0; font-size: 1rem; }
.unit-info p { margin: 0; font-size: 0.85rem; color: var(--c-text-mute); }
.unit-status { font-size: 0.75rem; color: var(--c-text-mute); }
.unit-status .icon { font-size: 1.1rem; }

/* --- Detalle de unidad --- */
.unit-detail-hero {
    text-align: center;
    margin-bottom: 1.5rem;
}
.unit-detail-hero h1 {
    color: var(--c-primary);
    font-size: 1.5rem;
    margin: 0.5rem 0 0.25rem 0;
}
.unit-detail-hero .unit-de {
    color: var(--c-text-mute);
    font-style: italic;
    font-size: 1.1rem;
    margin: 0;
}
.unit-image {
    max-width: 100%;
    border-radius: var(--r-radius);
    margin-bottom: 1rem;
}
.objectives {
    background: var(--c-primary-bg);
    border-radius: var(--r-radius);
    padding: 1rem 1.25rem;
    margin-bottom: 1.5rem;
}
.objectives h3 {
    color: var(--c-primary);
    margin: 0 0 0.5rem 0;
    font-size: 1rem;
}
.objectives ul {
    margin: 0;
    padding-left: 1.2rem;
    font-size: 0.92rem;
}
.objectives li { margin-bottom: 0.3rem; }

.lesson-list { display: grid; gap: 0.6rem; }
.lesson-card {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.85rem 1rem;
    background: var(--c-bg);
    border-radius: var(--r-radius);
    text-decoration: none;
    color: inherit;
    box-shadow: var(--shadow-sm);
    border-left: 3px solid var(--c-border);
}
.lesson-card.completed { border-left-color: var(--c-success); }
.lesson-card.current { border-left-color: var(--c-primary); background: var(--c-primary-bg); }
.lesson-card.locked { opacity: 0.5; cursor: not-allowed; }
.lesson-type-icon { font-size: 1.4rem; flex-shrink: 0; }
.lesson-info { flex: 1; }
.lesson-info h5 { margin: 0; font-size: 0.95rem; }
.lesson-info p { margin: 0.1rem 0 0 0; font-size: 0.8rem; color: var(--c-text-mute); }
.lesson-check { color: var(--c-success); font-size: 1.2rem; }

/* --- Lección activa --- */
.lesson-header {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 1rem;
    padding-bottom: 0.75rem;
    border-bottom: 1px solid var(--c-border);
}
.lesson-back {
    background: none;
    border: none;
    font-size: 1.4rem;
    cursor: pointer;
    color: var(--c-text-mute);
    padding: 0.25rem 0.5rem;
}
.lesson-title-bar { flex: 1; }
.lesson-title-bar h2 { margin: 0; font-size: 1.1rem; color: var(--c-primary); }
.lesson-title-bar p { margin: 0; font-size: 0.78rem; color: var(--c-text-mute); }

.progress-bar {
    width: 100%;
    height: 6px;
    background: var(--c-border);
    border-radius: 3px;
    overflow: hidden;
    margin-bottom: 1.5rem;
}
.progress-bar-fill {
    height: 100%;
    background: var(--c-primary);
    transition: width 0.3s ease;
}

.lesson-step {
    background: var(--c-bg);
    border-radius: var(--r-radius);
    padding: 1.5rem 1.25rem;
    box-shadow: var(--shadow-sm);
    margin-bottom: 1.5rem;
}
.lesson-step h3 {
    margin: 0 0 0.75rem 0;
    color: var(--c-primary);
    font-size: 1.1rem;
}
.lesson-step p { margin: 0 0 0.75rem 0; }

/* --- Cajas (info-box) --- */
.info-box {
    border-radius: var(--r-radius);
    padding: 0.85rem 1rem;
    margin: 1rem 0;
    border-left: 4px solid;
    font-size: 0.95rem;
}
.info-box-tip {
    background: var(--c-tip-bg);
    border-left-color: var(--c-tip-border);
}
.info-box-warn {
    background: var(--c-warn-bg);
    border-left-color: var(--c-warn-border);
}
.info-box-info {
    background: var(--c-info-bg);
    border-left-color: var(--c-info-border);
}

/* --- Diálogo --- */
.dialogue-box {
    background: var(--c-bg-soft);
    border-radius: var(--r-radius);
    padding: 1rem;
    margin: 0.75rem 0;
}
.dialogue-line {
    padding: 0.5rem 0;
    border-bottom: 1px solid var(--c-border);
}
.dialogue-line:last-child { border-bottom: none; }
.dialogue-speaker {
    font-weight: 600;
    color: var(--c-primary);
    font-size: 0.85rem;
    display: block;
    margin-bottom: 0.15rem;
}
.dialogue-de {
    font-size: 1rem;
    margin: 0.1rem 0;
}
.dialogue-es {
    color: var(--c-text-soft);
    font-style: italic;
    font-size: 0.9rem;
    margin: 0.1rem 0;
}
.dialogue-controls {
    display: flex;
    gap: 0.5rem;
    margin-top: 0.75rem;
    flex-wrap: wrap;
}

/* --- Tarjeta de vocabulario --- */
.vocab-card {
    background: var(--c-bg);
    border: 1px solid var(--c-border);
    border-radius: var(--r-radius);
    padding: 1.25rem;
    margin: 1rem 0;
    position: relative;
}
.vocab-card-de {
    color: var(--c-primary);
    font-weight: 600;
    font-size: 1.3rem;
    margin: 0 0 0.25rem 0;
}
.vocab-card-pron {
    color: var(--c-text-mute);
    font-family: var(--font-mono);
    font-size: 0.9rem;
    margin: 0 0 0.5rem 0;
}
.vocab-card-es {
    color: var(--c-text-soft);
    font-size: 1rem;
    margin: 0 0 0.75rem 0;
}
.vocab-card-actions {
    display: flex;
    gap: 0.5rem;
    align-items: center;
}
.star-btn {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    padding: 0.25rem;
    color: var(--c-text-mute);
    transition: color 0.15s, transform 0.15s;
}
.star-btn.starred {
    color: #f5b800;
}
.star-btn:active { transform: scale(1.2); }

/* --- Ejercicios --- */
.exercise {
    background: var(--c-bg);
    border-radius: var(--r-radius);
    padding: 1.25rem;
    margin-bottom: 1rem;
    box-shadow: var(--shadow-sm);
}
.exercise-instruction {
    font-weight: 500;
    margin: 0 0 1rem 0;
    color: var(--c-primary);
}
.exercise-question {
    font-size: 1.15rem;
    margin: 0.75rem 0 1rem 0;
    text-align: center;
    background: var(--c-bg-soft);
    padding: 1rem;
    border-radius: var(--r-radius);
}

/* Multiple choice / true-false buttons */
.option-list {
    display: grid;
    gap: 0.5rem;
}
.option-btn {
    text-align: left;
    padding: 0.85rem 1rem;
    background: var(--c-bg);
    border: 2px solid var(--c-border);
    border-radius: var(--r-radius);
    font-family: inherit;
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.15s;
    min-height: 48px;
}
.option-btn:hover { border-color: var(--c-primary); background: var(--c-primary-bg); }
.option-btn.selected { border-color: var(--c-primary); background: var(--c-primary-bg); }
.option-btn.correct {
    border-color: var(--c-success);
    background: var(--c-success-bg);
    color: var(--c-success);
    font-weight: 500;
}
.option-btn.incorrect {
    border-color: var(--c-error);
    background: var(--c-error-bg);
    color: var(--c-error);
}
.option-btn:disabled { cursor: not-allowed; }

/* Fill-in-the-blank */
.fill-blank-frame {
    display: flex;
    flex-wrap: wrap;
    gap: 0.3rem;
    align-items: center;
    background: var(--c-bg-soft);
    padding: 1rem;
    border-radius: var(--r-radius);
    margin: 0.75rem 0 1rem 0;
    font-size: 1.05rem;
    justify-content: center;
}
.fill-blank-input {
    padding: 0.5rem 0.75rem;
    border: 2px solid var(--c-primary);
    border-radius: var(--r-radius-sm);
    font-family: inherit;
    font-size: 1.05rem;
    min-width: 120px;
    text-align: center;
}

/* Match exercise */
.match-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0.5rem 1rem;
    margin: 1rem 0;
}
.match-item {
    padding: 0.75rem;
    background: var(--c-bg-soft);
    border: 2px solid var(--c-border);
    border-radius: var(--r-radius);
    cursor: pointer;
    font-size: 0.95rem;
    min-height: 48px;
    display: flex;
    align-items: center;
    transition: all 0.15s;
    word-break: break-word;
}
.match-item.selected {
    border-color: var(--c-primary);
    background: var(--c-primary-bg);
}
.match-item.matched {
    border-color: var(--c-success);
    background: var(--c-success-bg);
    color: var(--c-success);
    cursor: default;
    opacity: 0.7;
}

/* Order exercise */
.order-source, .order-target {
    display: flex;
    flex-wrap: wrap;
    gap: 0.4rem;
    padding: 0.75rem;
    border-radius: var(--r-radius);
    min-height: 50px;
    margin: 0.5rem 0;
}
.order-source { background: var(--c-bg-soft); border: 1px dashed var(--c-border); }
.order-target { background: var(--c-primary-bg); border: 2px solid var(--c-primary); }
.order-target:empty::before {
    content: "Toca las palabras en orden…";
    color: var(--c-text-mute);
    font-style: italic;
    font-size: 0.9rem;
}
.word-chip {
    padding: 0.5rem 0.85rem;
    background: var(--c-bg);
    border: 1px solid var(--c-border);
    border-radius: var(--r-radius-sm);
    cursor: pointer;
    font-size: 0.95rem;
    user-select: none;
    transition: all 0.1s;
}
.word-chip:hover { border-color: var(--c-primary); }
.word-chip.used { opacity: 0.3; pointer-events: none; }

/* Feedback */
.exercise-feedback {
    margin-top: 1rem;
    padding: 0.85rem 1rem;
    border-radius: var(--r-radius);
    font-size: 0.95rem;
    display: none;
}
.exercise-feedback.visible { display: block; }
.exercise-feedback.correct {
    background: var(--c-success-bg);
    color: var(--c-success);
    border-left: 4px solid var(--c-success);
}
.exercise-feedback.incorrect {
    background: var(--c-error-bg);
    color: var(--c-error);
    border-left: 4px solid var(--c-error);
}

.exercise-actions {
    display: flex;
    gap: 0.5rem;
    justify-content: flex-end;
    margin-top: 1rem;
}

/* Step navigation */
.step-nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 1.5rem;
    gap: 1rem;
}

/* Audio button */
.audio-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    background: var(--c-primary-bg);
    color: var(--c-primary);
    padding: 0.5rem 0.85rem;
    border-radius: var(--r-radius);
    border: none;
    cursor: pointer;
    font-size: 0.9rem;
    font-family: inherit;
}
.audio-btn:hover { background: var(--c-primary); color: white; }

/* Logro / fin de lección */
.lesson-complete {
    text-align: center;
    padding: 2rem 1rem;
}
.lesson-complete .check-icon {
    font-size: 4rem;
    color: var(--c-success);
    margin-bottom: 1rem;
}
.lesson-complete h2 {
    color: var(--c-primary);
    margin: 0 0 0.5rem 0;
}
.lesson-complete p {
    color: var(--c-text-soft);
    margin: 0 0 1.5rem 0;
}

/* Test score */
.test-score {
    text-align: center;
    padding: 2rem 1rem;
}
.test-score .score-big {
    font-size: 3rem;
    font-weight: 700;
    color: var(--c-primary);
    margin: 1rem 0;
}
.test-score .score-passed { color: var(--c-success); }
.test-score .score-failed { color: var(--c-error); }

/* Vocabulary list (página vocabulario) */
.vocab-grid {
    display: grid;
    gap: 0.75rem;
}

/* Kultur box */
.kultur-box {
    background: var(--c-info-bg);
    border-left: 4px solid var(--c-info-border);
    border-radius: var(--r-radius);
    padding: 1.25rem;
    margin: 1.5rem 0;
}
.kultur-box h3 {
    color: var(--c-info-border);
    margin: 0 0 0.5rem 0;
    font-size: 1.05rem;
}

/* Toast */
.toast {
    position: fixed;
    bottom: 5rem;
    left: 50%;
    transform: translateX(-50%) translateY(120%);
    background: var(--c-text);
    color: white;
    padding: 0.75rem 1.25rem;
    border-radius: var(--r-radius);
    box-shadow: var(--shadow-md);
    z-index: 200;
    transition: transform 0.25s;
    font-size: 0.9rem;
    max-width: 90vw;
    text-align: center;
}
.toast.visible {
    transform: translateX(-50%) translateY(0);
}

/* Empty state */
.empty-state {
    text-align: center;
    padding: 3rem 1rem;
    color: var(--c-text-mute);
}
.empty-state .icon {
    font-size: 3rem;
    margin-bottom: 1rem;
    opacity: 0.5;
}

/* Image placeholder */
.image-placeholder {
    background: var(--c-bg-soft);
    border: 1px dashed var(--c-border);
    border-radius: var(--r-radius);
    padding: 3rem 1rem;
    text-align: center;
    color: var(--c-text-mute);
    font-size: 0.9rem;
    margin: 1rem 0;
}

/* Responsive */
@media (max-width: 480px) {
    .app-main { padding: 1rem 0.75rem 5rem 0.75rem; }
    .match-container { grid-template-columns: 1fr; }
    .hero h1 { font-size: 1.5rem; }
    .vocab-card-de { font-size: 1.15rem; }
}

@media (min-width: 768px) {
    .header-inner, .app-main { max-width: 800px; }
    .app-nav { max-width: 800px; margin: 0 auto; left: 0; right: 0; }
}

/* Print friendly (hide nav) */
@media print {
    .app-nav, .app-header, .lesson-back, .step-nav { display: none !important; }
}

/* Focus visible */
:focus-visible {
    outline: 3px solid var(--c-primary);
    outline-offset: 2px;
}