/* Premium Dark Mode Design */
:root {
    --bg-color: #0c0c0e;
    --card-bg: #16161a;
    --text-primary: #fffffe;
    --text-secondary: #94a1b2;
    --accent: #7f5af0;
    --accent-glow: rgba(127, 90, 240, 0.4);
    --success: #2cb67d;
    --border-color: #2b2c34;
    --glass-bg: rgba(22, 22, 26, 0.7);
    --font-heading: 'Inter', sans-serif;
    --font-body: 'Merriweather', serif;
    --ease: cubic-bezier(0.23, 1, 0.32, 1);
}

body {
    background-color: var(--bg-color);
    background-image:
        radial-gradient(circle at 10% 20%, rgba(127, 90, 240, 0.05) 0%, transparent 40%),
        radial-gradient(circle at 90% 80%, rgba(44, 182, 125, 0.05) 0%, transparent 40%);
    color: var(--text-primary);
    font-family: var(--font-heading);
    line-height: 1.6;
    margin: 0;
    min-height: 100vh;
}

#app {
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
}

/* Nav */
.main-nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 0;
    margin-bottom: 40px;
}

.logo {
    font-weight: 800;
    font-size: 1.5rem;
    letter-spacing: -1px;
}

.logo span {
    color: var(--accent);
}

.nav-links button {
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 1rem;
    margin-left: 20px;
    cursor: pointer;
    font-weight: 500;
    transition: color 0.2s;
}

.nav-links button.active {
    color: var(--text-primary);
    border-bottom: 2px solid var(--accent);
}

/* Typography */
h1,
h2,
h3 {
    line-height: 1.1;
    margin-bottom: 0.5em;
    letter-spacing: -0.02em;
}

h1 {
    font-size: 3rem;
    background: -webkit-linear-gradient(0deg, #fff, #94a1b2);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* Cards & Glass */
.card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    padding: 24px;
    margin-bottom: 24px;
    transition: transform 0.3s var(--ease);
}

.card.glass {
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
}

.card:hover {
    transform: translateY(-3px);
    border-color: var(--accent);
    box-shadow: 0 10px 40px -10px rgba(0, 0, 0, 0.5);
}

/* Stats */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 15px;
    margin: 40px 0;
}

.stat-box {
    background: rgba(255, 255, 255, 0.03);
    padding: 15px;
    border-radius: 12px;
    text-align: center;
    border: 1px solid transparent;
}

.stat-box:hover {
    border-color: var(--border-color);
    background: rgba(255, 255, 255, 0.05);
}

.stat-value {
    display: block;
    font-size: 2.2rem;
    font-weight: 800;
    color: var(--accent);
}

.stat-label {
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--text-secondary);
}

/* Buttons */
.btn-primary {
    background: var(--accent);
    color: white;
    border: none;
    padding: 16px 40px;
    border-radius: 50px;
    font-size: 1.2rem;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.3s var(--ease);
    box-shadow: 0 0 20px var(--accent-glow);
}

.btn-primary:hover {
    transform: scale(1.05);
    box-shadow: 0 0 30px var(--accent-glow);
}

.btn-pulse {
    animation: pulse-glow 2s infinite;
}

@keyframes pulse-glow {
    0% {
        box-shadow: 0 0 0 0 rgba(127, 90, 240, 0.7);
    }

    70% {
        box-shadow: 0 0 0 15px rgba(127, 90, 240, 0);
    }

    100% {
        box-shadow: 0 0 0 0 rgba(127, 90, 240, 0);
    }
}

/* Badges */
.badge {
    display: inline-block;
    background: rgba(44, 182, 125, 0.15);
    color: var(--success);
    padding: 4px 10px;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
    margin-bottom: 10px;
    border: 1px solid rgba(44, 182, 125, 0.3);
}

.badge.small {
    font-size: 0.7rem;
    padding: 2px 8px;
}

/* AI Summary */
.ai-summary {
    font-family: var(--font-body);
    font-style: italic;
    line-height: 1.8;
    color: #eaeaec;
}

/* Forms */
textarea {
    width: 100%;
    background: rgba(0, 0, 0, 0.3);
    border: 1px solid var(--border-color);
    color: white;
    padding: 15px;
    border-radius: 10px;
    font-family: var(--font-body);
    margin: 15px 0;
}

input[type=range] {
    width: 100%;
    accent-color: var(--accent);
    cursor: pointer;
    height: 6px;
}

/* Utilities */
.loading-spinner {
    color: var(--accent);
    font-weight: 600;
    text-align: center;
    padding: 20px;
}

.exercise-intro {
    color: var(--text-secondary);
    margin-bottom: 30px;
    font-style: italic;
}

.exercise-focus {
    background: rgba(127, 90, 240, 0.05);
    border-left: 3px solid var(--accent);
    padding: 15px;
    font-size: 0.95rem;
}

.step {
    display: flex;
    margin-bottom: 20px;
}

.step-number {
    background: var(--border-color);
    width: 28px;
    height: 28px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-right: 15px;
    font-weight: 700;
    font-size: 0.9rem;
    flex-shrink: 0;
}