:root {
    --card-bg: var(--bg-color);
    --border-color: var(--sidebar-border);
}

.container {
    max-width: 1000px;
    margin: 100px auto 50px;
    padding: 0 20px;
}

.hero {
    text-align: center;
    margin-bottom: 50px;
}

.hero h1 {
    font-size: 3rem;
    font-weight: 800;
    margin-bottom: 20px;
    background: linear-gradient(135deg, #6366f1, #a855f7);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero p {
    font-size: 1.2rem;
    color: var(--text-muted);
}

.generator-grid {
    display: grid;
    grid-template-columns: 1.5fr 1fr;
    gap: 30px;
}

.input-card, .settings-card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 24px;
    padding: 30px;
    box-shadow: var(--shadow-md);
}

/* Tabs */
.tabs {
    display: flex;
    gap: 10px;
    margin-bottom: 20px;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 10px;
}

.tab-btn {
    background: none;
    border: none;
    padding: 10px 20px;
    font-weight: 600;
    color: var(--text-muted);
    cursor: pointer;
    transition: var(--transition);
    border-radius: 8px;
}

.tab-btn.active {
    background: var(--hover-bg);
    color: #6366f1;
}

.tab-content { display: none; }
.tab-content.active { display: block; }

#text-input {
    width: 100%;
    height: 250px;
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 15px;
    background: var(--sidebar-bg);
    color: var(--text-color);
    resize: none;
    font-family: inherit;
    font-size: 1rem;
}

.upload-zone {
    border: 2px dashed var(--border-color);
    border-radius: 12px;
    padding: 60px;
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
}

.upload-zone:hover {
    border-color: #6366f1;
    background: rgba(99, 102, 241, 0.05);
}

/* Flashcard Styles */
.flashcard-container {
    perspective: 1000px;
    max-width: 600px;
    height: 400px;
    margin: 40px auto;
}

.flashcard {
    width: 100%;
    height: 100%;
    position: relative;
    transform-style: preserve-3d;
    transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
    cursor: pointer;
}

.flashcard.flipped {
    transform: rotateY(180deg);
}

.card-face {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 40px;
    border-radius: 30px;
    box-shadow: 0 20px 40px rgba(0,0,0,0.1);
    border: 2px solid var(--border-color);
    background: var(--card-bg);
    transition: var(--transition);
}

.card-face:hover {
    border-color: #6366f1;
}

.speak-btn {
    position: absolute;
    top: 25px;
    right: 25px;
    background: rgba(99, 102, 241, 0.1);
    border: none;
    width: 45px;
    height: 45px;
    border-radius: 50%;
    cursor: pointer;
    font-size: 1.2rem;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
    z-index: 10;
}

.speak-btn:hover {
    background: #6366f1;
    color: white;
    transform: scale(1.1);
}

.card-back {
    transform: rotateY(180deg);
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.05), rgba(168, 85, 247, 0.05));
    border-color: #6366f1;
}

.card-label {
    position: absolute;
    top: 30px;
    left: 40px;
    font-size: 0.75rem;
    font-weight: 800;
    color: var(--text-muted);
    letter-spacing: 2px;
    text-transform: uppercase;
    opacity: 0.6;
}

.card-text {
    font-size: 1.8rem;
    font-weight: 700;
    text-align: center;
    line-height: 1.4;
}

.card-hint {
    position: absolute;
    bottom: 30px;
    font-size: 0.85rem;
    color: var(--text-muted);
    opacity: 0.6;
}

.cards-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 600px;
    margin: 0 auto;
}

.progress-info {
    font-weight: 700;
    font-size: 1.1rem;
    color: #6366f1;
}

.cards-nav {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-top: 30px;
}

/* Animations */
.fade-in { animation: fadeIn 0.5s ease; }
@keyframes fadeIn { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: translateY(0); } }

/* Collections Grid */
.collections-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 20px;
    margin-top: 30px;
}

.collection-card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    padding: 24px;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: 10px;
}

.collection-card:hover {
    transform: translateY(-5px);
    border-color: #6366f1;
    box-shadow: 0 10px 25px rgba(99, 102, 241, 0.1);
}

.collection-card.new-btn {
    border: 2px dashed #6366f1;
    background: rgba(99, 102, 241, 0.02);
}

.plus-icon {
    font-size: 2.5rem;
    color: #6366f1;
    font-weight: 300;
}

.premium-input {
    width: 100%;
    padding: 14px;
    border-radius: 12px;
    border: 1px solid var(--border-color);
    background: var(--sidebar-bg);
    color: var(--text-color);
    font-size: 1rem;
    outline: none;
    transition: var(--transition);
}

.premium-input:focus {
    border-color: #6366f1;
    box-shadow: 0 0 0 4px rgba(99, 102, 241, 0.1);
}

.section-header {
    margin-bottom: 30px;
    display: flex;
    align-items: center;
    gap: 20px;
}

.generate-main-btn {
    width: 100%;
    padding: 18px;
    background: linear-gradient(135deg, #6366f1, #a855f7);
    color: white;
    border: none;
    border-radius: 16px;
    font-weight: 700;
    font-size: 1.1rem;
    cursor: pointer;
    box-shadow: 0 10px 20px rgba(99, 102, 241, 0.2);
    transition: var(--transition);
    display: flex;
    justify-content: center;
    align-items: center;
}

.generate-main-btn:hover { transform: translateY(-3px); box-shadow: 0 15px 30px rgba(99, 102, 241, 0.3); }

/* Loader */
.loader-dots { display: flex; gap: 5px; margin-left: 10px; }
.loader-dots span { width: 8px; height: 8px; background: white; border-radius: 50%; animation: bounce 0.5s infinite alternate; }
.loader-dots span:nth-child(2) { animation-delay: 0.2s; }
.loader-dots span:nth-child(3) { animation-delay: 0.4s; }
@keyframes bounce { from { transform: translateY(0); opacity: 0.5; } to { transform: translateY(-5px); opacity: 1; } }

body {
    background-image: radial-gradient(var(--border-color) 0.5px, transparent 0.5px);
    background-size: 20px 20px;
}

@media (max-width: 768px) {
    .generator-grid { grid-template-columns: 1fr; }
    .flashcard-container { height: 350px; margin: 20px auto; }
    .card-text { font-size: 1.4rem; padding: 20px; }
    .hero h1 { font-size: 2.2rem; }
    .container { margin-top: 60px; }
}

.delete-btn {
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: var(--transition);
}

.delete-btn:hover {
    background: #dc2626 !important;
}

.premium-input::placeholder {
    font-style: italic;
    opacity: 0.5;
}