:root {
    --primary: #4f46e5;
    --primary-hover: #4338ca;
    --success: #10b981;
    --success-hover: #059669;
    --danger: #ef4444;
    --warning: #f59e0b;
    --bg-color: #f4f4f9;
    --card-bg: #ffffff;
    --text-main: #1f2937;
    --text-muted: #6b7280;
    --border: #e5e7eb;
    --radius: 12px;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

body {
    background-color: var(--bg-color);
    color: var(--text-main);
    line-height: 1.5;
}

header {
    background-color: var(--card-bg);
    padding: 1rem 2rem;
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: sticky;
    top: 0;
    z-index: 10;
}

.header-actions {
    display: flex;
    gap: 1rem;
    align-items: center;
}

h1 {
    font-size: 1.25rem;
    color: var(--primary);
}

.container {
    max-width: 600px;
    margin: 2rem auto;
    padding: 0 1rem;
}

/* Utilitários */
.hidden { display: none !important; }
.hidden-input { display: none; }

/* Botões */
button, .import-label {
    cursor: pointer;
    border: none;
    border-radius: 8px;
    padding: 0.75rem 1rem;
    font-size: 1rem;
    font-weight: 600;
    transition: background-color 0.2s;
    text-align: center;
    display: inline-block;
}

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

.btn-success { background-color: var(--success); color: white; width: 100%; }
.btn-success:hover { background-color: var(--success-hover); }

.btn-secondary { background-color: #e5e7eb; color: var(--text-main); }
.btn-secondary:hover { background-color: #d1d5db; }

.btn-text { background-color: transparent; color: var(--primary); padding: 0.5rem; }
.btn-text:hover { background-color: #f3f4f6; }

.btn-large { width: 100%; padding: 1rem; font-size: 1.1rem; }

/* Upload Moderno */
.file-upload-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.75rem;
    border: 2px dashed var(--border);
    border-radius: 8px;
    color: var(--text-muted);
    cursor: pointer;
    transition: all 0.2s;
    font-size: 0.9rem;
    background: #fafafa;
}

.file-upload-btn:hover {
    border-color: var(--primary);
    color: var(--primary);
    background: #f0f4ff;
}

/* Dashboard */
.create-deck-container {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 2rem;
}

input[type="text"], textarea {
    flex: 1;
    padding: 0.75rem;
    border: 1px solid var(--border);
    border-radius: 8px;
    font-size: 1rem;
    outline: none;
    resize: vertical;
}

input[type="text"]:focus, textarea:focus {
    border-color: var(--primary);
}

.deck-grid { display: grid; gap: 1rem; }

.deck-card {
    background: var(--card-bg);
    padding: 1.5rem;
    border-radius: var(--radius);
    box-shadow: 0 4px 6px -1px rgba(0,0,0,0.05);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.deck-info h3 { margin-bottom: 0.25rem; }
.deck-info p { color: var(--text-muted); font-size: 0.875rem; }

/* Form Editor */
.card-form {
    background: var(--card-bg);
    padding: 1.5rem;
    border-radius: var(--radius);
    margin-top: 1.5rem;
    box-shadow: 0 4px 6px -1px rgba(0,0,0,0.05);
}

.form-group {
    margin-bottom: 1.5rem;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.form-group label:first-child {
    font-weight: 600;
    color: var(--text-main);
}

.editor-actions { margin-top: 1.5rem; }
.card-count { text-align: center; margin-top: 1rem; color: var(--text-muted); }

/* Study View & Typography */
.study-progress {
    text-align: center;
    margin-bottom: 1rem;
    font-weight: 600;
    color: var(--text-muted);
}

.flashcard {
    background: var(--card-bg);
    border-radius: var(--radius);
    padding: 2.5rem 1.5rem;
    min-height: 350px;
    box-shadow: 0 10px 15px -3px rgba(0,0,0,0.1);
    margin-bottom: 1.5rem;
    display: flex;
    flex-direction: column;
    justify-content: center;
    position: relative;
}

.flashcard.interactive {
    cursor: pointer;
    transition: transform 0.1s;
}
.flashcard.interactive:active { transform: scale(0.99); }

.card-side { text-align: center; font-size: 1.1rem; font-weight: 400; }

/* Tipografia Dinâmica da Frente */
.text-large { font-size: 1.5rem; font-weight: 700; color: var(--primary); }

.card-side img {
    max-width: 100%;
    max-height: 250px;
    object-fit: contain;
    margin-top: 1.5rem;
    border-radius: 8px;
}

#card-divider {
    border: 0;
    border-top: 2px dashed var(--border);
    margin: 2rem 0;
}

.flip-hint {
    position: absolute;
    bottom: 10px;
    left: 0;
    right: 0;
    text-align: center;
    font-size: 0.8rem;
    color: var(--text-muted);
    opacity: 0.5;
}

/* Review Controls */
.study-controls { display: flex; flex-direction: column; gap: 1rem; }

#review-controls {
    text-align: center;
    background: var(--card-bg);
    padding: 1rem;
    border-radius: var(--radius);
    box-shadow: 0 2px 5px rgba(0,0,0,0.05);
}

.review-title {
    margin-bottom: 1rem;
    color: var(--text-main);
    font-size: 1rem;
}

.review-buttons { display: flex; gap: 0.5rem; }

.btn-review { flex: 1; padding: 1rem 0; color: white; }
.btn-bad { background-color: var(--danger); }
.btn-bad:hover { background-color: #dc2626; }
.btn-ok { background-color: rgb(169, 169, 169); }
.btn-ok:hover { background-color: #d97706; }
.btn-good { background-color: var(--success); }
.btn-good:hover { background-color: var(--success-hover); }