/* ===== CSS Reset ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* ===== Design Tokens ===== */
:root {
    /* Colors */
    --bg-dark: hsl(220, 20%, 10%);
    --bg-card: hsl(220, 18%, 15%);
    --primary: hsl(200, 90%, 55%);
    --primary-dark: hsl(200, 80%, 45%);
    --accent: hsl(40, 95%, 60%);
    --text-light: hsl(0, 0%, 95%);
    --text-muted: hsl(0, 0%, 70%);
    --border: hsl(220, 15%, 25%);

    /* Typography */
    --font-japanese: 'Noto Sans JP', 'Hiragino Sans', 'Meiryo', sans-serif;
    --font-system: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;

    /* Spacing */
    --space-xs: 0.5rem;
    --space-sm: 1rem;
    --space-md: 1.5rem;
    --space-lg: 2rem;
    --space-xl: 3rem;

    /* Border Radius */
    --radius-sm: 0.5rem;
    --radius-md: 1rem;
    --radius-lg: 1.5rem;
}

/* ===== Base Styles ===== */
body {
    background: linear-gradient(135deg, var(--bg-dark) 0%, hsl(220, 25%, 12%) 100%);
    color: var(--text-light);
    font-family: var(--font-system);
    min-height: 100vh;
    padding: var(--space-md);
}

.container {
    max-width: 100%;
    margin: 0 auto;
    padding: 0 1rem;
}

/* Keep builder mode content narrower for readability */
#builder-mode {
    max-width: 900px;
    margin: 0 auto;
}

/* ===== Header ===== */
.header {
    text-align: center;
    margin-bottom: var(--space-xl);
}

.title {
    font-family: var(--font-japanese);
    font-size: 2.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary), var(--accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--space-xs);
}

.subtitle {
    color: var(--text-muted);
    font-size: 1.125rem;
    letter-spacing: 0.1em;
}

/* ===== Mode Selector ===== */
.mode-selector {
    display: flex;
    gap: var(--space-sm);
    margin-bottom: var(--space-lg);
    background: var(--bg-card);
    padding: var(--space-xs);
    border-radius: var(--radius-md);
}

.mode-btn {
    flex: 1;
    padding: var(--space-sm) var(--space-md);
    border: none;
    background: transparent;
    color: var(--text-muted);
    font-size: 1rem;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all 0.3s ease;
}

.mode-btn:hover {
    color: var(--text-light);
    background: rgba(255, 255, 255, 0.05);
}

.mode-btn.active {
    background: var(--primary);
    color: white;
    font-weight: 600;
}

.mode-btn small {
    display: block;
    font-size: 0.75rem;
    opacity: 0.8;
    margin-top: 0.25rem;
}

/* ===== Mode Containers ===== */
.mode-container {
    display: none;
}

.mode-container.active {
    display: block;
}

/* ===== Scenario Selector ===== */
.scenario-selector {
    margin-bottom: var(--space-lg);
}

.scenario-selector label {
    display: block;
    margin-bottom: var(--space-xs);
    color: var(--text-muted);
    font-size: 0.875rem;
}

.scenario-selector select {
    width: 100%;
    padding: var(--space-sm);
    background: var(--bg-card);
    border: 2px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--text-light);
    font-size: 1rem;
    font-family: var(--font-japanese);
    cursor: pointer;
    transition: border-color 0.3s ease;
}

.scenario-selector select:focus {
    outline: none;
    border-color: var(--primary);
}

.scenario-selector option {
    padding: var(--space-sm);
}

/* ===== Progress Bar ===== */
.progress-bar {
    display: flex;
    gap: var(--space-sm);
    margin-bottom: var(--space-xl);
}

.progress-step {
    flex: 1;
    text-align: center;
    padding: var(--space-sm);
    background: var(--bg-card);
    border-radius: var(--radius-sm);
    border: 2px solid var(--border);
    color: var(--text-muted);
    font-size: 0.875rem;
    transition: all 0.3s ease;
    cursor: pointer;
}

.progress-step:hover {
    border-color: var(--primary);
    background: rgba(56, 189, 248, 0.05);
    transform: translateY(-2px);
}

.progress-step.active {
    border-color: var(--primary);
    background: linear-gradient(135deg, rgba(56, 189, 248, 0.1), rgba(59, 130, 246, 0.1));
    color: var(--primary);
    font-weight: 600;
}

.progress-step.completed {
    border-color: var(--accent);
    background: rgba(251, 191, 36, 0.1);
    color: var(--accent);
}

/* ===== Sentence Display ===== */
.sentence-display {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
    margin-bottom: var(--space-lg);
    text-align: center;
    min-height: 350px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: var(--space-md);
}

.visual-cue {
    font-size: 4rem;
    margin-bottom: var(--space-sm);
    animation: float 3s ease-in-out infinite;
}

@keyframes float {

    0%,
    100% {
        transform: translateY(0);
    }

    50% {
        transform: translateY(-10px);
    }
}

.japanese-sentence {
    font-family: var(--font-japanese);
    font-size: 2.5rem;
    line-height: 1.6;
    color: var(--text-light);
    font-weight: 700;
    margin: var(--space-md) 0;
}

/* Ruby (Furigana) Styling */
ruby {
    ruby-align: center;
}

rt {
    font-size: 0.5em;
    color: var(--primary);
    font-weight: 400;
}

.english-translation {
    font-size: 1.25rem;
    color: var(--text-muted);
    margin-top: var(--space-sm);
}

.grammar-hint {
    color: var(--accent);
    font-size: 0.875rem;
    margin-top: var(--space-md);
    font-style: italic;
}

/* ===== Controls ===== */
.controls {
    display: flex;
    flex-direction: column;
    gap: var(--space-lg);
    margin-bottom: var(--space-lg);
}

/* Form Toggle (Polite/Casual) */
.form-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-sm);
}

.switch {
    position: relative;
    display: inline-block;
    width: 60px;
    height: 34px;
}

.switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

.slider {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: var(--border);
    transition: 0.4s;
    border-radius: 34px;
}

.slider:before {
    position: absolute;
    content: "";
    height: 26px;
    width: 26px;
    left: 4px;
    bottom: 4px;
    background-color: white;
    transition: 0.4s;
    border-radius: 50%;
}

input:checked+.slider {
    background-color: var(--primary);
}

input:checked+.slider:before {
    transform: translateX(26px);
}

.toggle-label {
    font-size: 1rem;
    color: var(--text-light);
}

/* Navigation Buttons */
.nav-buttons {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-sm);
}

.step-indicator {
    color: var(--text-muted);
    font-size: 0.875rem;
}

.btn {
    padding: var(--space-sm) var(--space-lg);
    border: none;
    border-radius: var(--radius-sm);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
}

.btn-primary {
    background: var(--primary);
    color: white;
}

.btn-primary:hover:not(:disabled) {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(56, 189, 248, 0.3);
}

.btn-secondary {
    background: var(--bg-card);
    color: var(--text-light);
    border: 2px solid var(--border);
}

.btn-secondary:hover:not(:disabled) {
    border-color: var(--primary);
    transform: translateY(-2px);
}

.btn:disabled {
    opacity: 0.4;
    cursor: not-allowed;
}

.btn-outline {
    background: transparent;
    color: var(--text-light);
    border: 2px solid var(--border);
}

.btn-outline:hover {
    border-color: var(--accent);
    color: var(--accent);
}

/* Reset Section */
.reset-section {
    text-align: center;
}

/* Coming Soon (Immersion Mode) */
.coming-soon {
    text-align: center;
    padding: var(--space-xl);
    background: var(--bg-card);
    border-radius: var(--radius-lg);
}

.coming-soon h2 {
    margin-bottom: var(--space-md);
    color: var(--primary);
}

.coming-soon p {
    color: var(--text-muted);
    margin: var(--space-sm) 0;
}

/* ===== Responsive Design ===== */
@media (max-width: 768px) {
    .title {
        font-size: 2rem;
    }

    .japanese-sentence {
        font-size: 2rem;
    }

    .sentence-display {
        padding: var(--space-lg);
        min-height: 300px;
    }

    .nav-buttons {
        flex-direction: column;
    }

    .btn {
        width: 100%;
    }
}