:root {
    --bg-color: #0f172a;
    --text-color: #e2e8f0;
    --card-bg: rgba(30, 41, 59, 0.7);
    --card-border: rgba(148, 163, 184, 0.1);
    --accent-color: #38bdf8;
    --accent-hover: #0ea5e9;
    --success-color: #10b981;
    --glow-color: rgba(56, 189, 248, 0.5);
    --font-heading: 'Outfit', sans-serif;
    --font-body: 'Inter', sans-serif;
    --transition-speed: 0.3s;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: var(--font-body);
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    overflow-x: hidden;
    background-image:
        radial-gradient(circle at 10% 20%, rgba(56, 189, 248, 0.1) 0%, transparent 40%),
        radial-gradient(circle at 90% 80%, rgba(139, 92, 246, 0.1) 0%, transparent 40%);
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

/* Header */
header {
    text-align: center;
    margin-bottom: 3rem;
    position: relative;
    padding: 2rem 0;
}

header h1 {
    font-family: var(--font-heading);
    font-size: 3rem;
    font-weight: 700;
    background: linear-gradient(135deg, #38bdf8 0%, #818cf8 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 0.5rem;
    text-shadow: 0 0 30px rgba(56, 189, 248, 0.3);
}

header p {
    font-size: 1.1rem;
    color: #94a3b8;
}

/* Dashboard */
.dashboard {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin-bottom: 3rem;
}

.stat-card {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    backdrop-filter: blur(12px);
    border-radius: 16px;
    padding: 1.5rem;
    text-align: center;
    transition: transform var(--transition-speed), box-shadow var(--transition-speed);
}

.stat-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px -10px rgba(0, 0, 0, 0.5);
    border-color: rgba(56, 189, 248, 0.3);
}

.stat-value {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--accent-color);
    margin-bottom: 0.5rem;
    font-family: var(--font-heading);
}

.stat-label {
    color: #94a3b8;
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 1px;
}

/* Progress Bar */
.progress-container {
    background: rgba(30, 41, 59, 0.5);
    border-radius: 20px;
    height: 12px;
    width: 100%;
    margin-bottom: 3rem;
    overflow: hidden;
    position: relative;
}

.progress-bar {
    height: 100%;
    background: linear-gradient(90deg, #38bdf8, #818cf8);
    width: 0%;
    border-radius: 20px;
    transition: width 1s ease-in-out;
    box-shadow: 0 0 10px var(--glow-color);
}

/* Phases */
.phase {
    margin-bottom: 4rem;
}

.phase-header {
    margin-bottom: 1.5rem;
    padding-left: 1rem;
    border-left: 4px solid var(--accent-color);
}

.phase-title {
    font-family: var(--font-heading);
    font-size: 1.8rem;
    margin-bottom: 0.5rem;
    color: #fff;
}

.phase-desc {
    color: #94a3b8;
}

.grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
}

/* Day Card */
.day-card {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    backdrop-filter: blur(8px);
    border-radius: 12px;
    padding: 1.5rem;
    position: relative;
    transition: all var(--transition-speed);
    cursor: pointer;
    overflow: hidden;
}

.day-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: linear-gradient(90deg, transparent, rgba(56, 189, 248, 0.5), transparent);
    transform: translateX(-100%);
    transition: transform 0.5s;
}

.day-card:hover::before {
    transform: translateX(100%);
}

.day-card:hover {
    transform: translateY(-3px);
    background: rgba(40, 50, 70, 0.8);
    border-color: rgba(56, 189, 248, 0.2);
}

.day-card.completed {
    border-color: var(--success-color);
    background: rgba(16, 185, 129, 0.05);
}

.day-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

.day-number {
    font-size: 0.9rem;
    color: var(--accent-color);
    font-weight: 600;
    text-transform: uppercase;
}

.checkbox-visual {
    width: 24px;
    height: 24px;
    border: 2px solid #475569;
    border-radius: 6px;
    transition: all 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
}

.day-card.completed .checkbox-visual {
    background: var(--success-color);
    border-color: var(--success-color);
    box-shadow: 0 0 10px rgba(16, 185, 129, 0.4);
}

.checkbox-visual::after {
    content: '✓';
    color: white;
    font-size: 14px;
    opacity: 0;
    transform: scale(0.5);
    transition: all 0.2s;
}

.day-card.completed .checkbox-visual::after {
    opacity: 1;
    transform: scale(1);
}

.day-topic {
    font-size: 1.1rem;
    font-weight: 500;
    color: #e2e8f0;
    margin-bottom: 0.5rem;
}

.day-details {
    font-size: 0.9rem;
    color: #94a3b8;
    line-height: 1.4;
}

/* Modal Styling */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow: auto;
    background-color: rgba(0, 0, 0, 0.8);
    backdrop-filter: blur(5px);
    align-items: center;
    justify-content: center;
}

.modal.active {
    display: flex;
    animation: fadeIn 0.3s ease-out;
}

.modal-content {
    background: #1e293b;
    border: 1px solid rgba(56, 189, 248, 0.3);
    margin: auto;
    padding: 2.5rem;
    border-radius: 16px;
    width: 90%;
    max-width: 600px;
    position: relative;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
}

.close-modal {
    position: absolute;
    top: 1rem;
    right: 1.5rem;
    color: #94a3b8;
    font-size: 2rem;
    font-weight: bold;
    cursor: pointer;
    transition: color 0.2s;
}

.close-modal:hover {
    color: #fff;
}

#modalTitle {
    color: var(--accent-color);
    font-family: var(--font-heading);
    margin-bottom: 1.5rem;
    font-size: 1.8rem;
    border-bottom: 1px solid rgba(148, 163, 184, 0.2);
    padding-bottom: 0.5rem;
}

#modalList {
    list-style-type: none;
    margin-bottom: 2rem;
}

#modalList li {
    padding: 0.8rem 0;
    border-bottom: 1px dashed rgba(148, 163, 184, 0.1);
    font-size: 1.05rem;
    display: flex;
    align-items: center;
}

#modalList li::before {
    content: '•';
    color: var(--accent-color);
    font-weight: bold;
    display: inline-block;
    width: 1em;
    margin-left: -1em;
}

.modal-btn {
    display: block;
    width: 100%;
    padding: 1rem;
    border-radius: 8px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    border: none;
    font-family: var(--font-heading);
}

.modal-btn.primary {
    background: linear-gradient(135deg, #38bdf8 0%, #818cf8 100%);
    color: white;
}

.modal-btn.primary:hover {
    opacity: 0.9;
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(56, 189, 248, 0.3);
}

.modal-btn.secondary {
    background: rgba(16, 185, 129, 0.2);
    color: #10b981;
    border: 1px solid #10b981;
}

.modal-btn.secondary:hover {
    background: rgba(16, 185, 129, 0.3);
}

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.day-card {
    animation: fadeIn 0.5s ease-out forwards;
}

/* Responsive */
@media (max-width: 768px) {
    header h1 {
        font-size: 2rem;
    }

    .container {
        padding: 1rem;
    }

    .dashboard {
        grid-template-columns: 1fr;
    }
}