/* ==================== Design Tokens ==================== */
:root {
    /* Colors - Vibrant & Modern Palette */
    --color-bg-primary: #0a0a0f;
    --color-bg-secondary: #13131a;
    --color-bg-card: rgba(25, 25, 35, 0.8);
    --color-bg-card-hover: rgba(35, 35, 50, 0.95);

    --color-accent-primary: #6366f1;
    --color-accent-secondary: #8b5cf6;
    --color-accent-tertiary: #ec4899;
    --color-accent-success: #10b981;
    --color-accent-warning: #f59e0b;

    --color-text-primary: #f8f9fa;
    --color-text-secondary: #b4b4c8;
    --color-text-muted: #7a7a90;

    --gradient-primary: linear-gradient(135deg, #6366f1 0%, #8b5cf6 50%, #ec4899 100%);
    --gradient-secondary: linear-gradient(135deg, #0ea5e9 0%, #6366f1 100%);
    --gradient-card: linear-gradient(135deg, rgba(99, 102, 241, 0.1) 0%, rgba(139, 92, 246, 0.1) 100%);

    /* Typography */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-mono: 'JetBrains Mono', 'Courier New', monospace;

    /* Spacing */
    --space-xs: 0.5rem;
    --space-sm: 1rem;
    --space-md: 1.5rem;
    --space-lg: 2rem;
    --space-xl: 3rem;
    --space-2xl: 4rem;

    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;

    /* Shadows */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.2);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.4);
    --shadow-glow: 0 0 32px rgba(99, 102, 241, 0.3);

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 250ms ease;
    --transition-slow: 400ms ease;
}

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

body {
    font-family: var(--font-primary);
    background: var(--color-bg-primary);
    color: var(--color-text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    position: relative;
}

/* ==================== Animated Stars Background ==================== */
.stars {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 0;
}

.stars::before,
.stars::after {
    content: '';
    position: absolute;
    width: 2px;
    height: 2px;
    background: var(--color-text-primary);
    border-radius: 50%;
    box-shadow:
        100px 200px #fff, 300px 100px #fff, 500px 300px #fff,
        700px 150px #fff, 900px 250px #fff, 1100px 180px #fff,
        200px 400px #fff, 400px 350px #fff, 600px 450px #fff,
        800px 380px #fff, 1000px 420px #fff, 1200px 390px #fff,
        150px 600px #fff, 350px 550px #fff, 550px 650px #fff,
        750px 580px #fff, 950px 620px #fff, 1150px 590px #fff;
    animation: twinkle 3s ease-in-out infinite;
}

.stars::after {
    animation-delay: 1.5s;
    box-shadow:
        50px 250px #fff, 250px 150px #fff, 450px 350px #fff,
        650px 200px #fff, 850px 300px #fff, 1050px 230px #fff,
        150px 450px #fff, 350px 400px #fff, 550px 500px #fff,
        750px 430px #fff, 950px 470px #fff, 1150px 440px #fff;
}

@keyframes twinkle {
    0%, 100% { opacity: 0.3; }
    50% { opacity: 1; }
}

/* ==================== Container ==================== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--space-xl) var(--space-md);
    position: relative;
    z-index: 1;
}

/* ==================== Header ==================== */
.journal-header {
    text-align: center;
    margin-bottom: var(--space-2xl);
    animation: fadeInDown 0.8s ease;
}

@keyframes fadeInDown {
    from {
        opacity: 0;
        transform: translateY(-30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.header-content {
    background: var(--gradient-card);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(99, 102, 241, 0.2);
    border-radius: var(--radius-xl);
    padding: var(--space-xl);
    box-shadow: var(--shadow-lg), var(--shadow-glow);
}

.main-title {
    font-size: clamp(2rem, 5vw, 3.5rem);
    font-weight: 700;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--space-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-sm);
}

.title-icon {
    font-size: 1.2em;
    animation: bounce 2s ease-in-out infinite;
}

@keyframes bounce {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
}

.subtitle {
    font-size: 1.25rem;
    color: var(--color-text-secondary);
    margin-bottom: var(--space-md);
    font-weight: 300;
}

.resources-section {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
    margin-bottom: var(--space-md);
    padding: var(--space-md);
    background: rgba(99, 102, 241, 0.05);
    border: 1px solid rgba(99, 102, 241, 0.15);
    border-radius: var(--radius-md);
}

.resource-item {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    flex-wrap: wrap;
}

.resource-label {
    font-size: 0.9rem;
    color: var(--color-text-secondary);
    font-weight: 500;
    white-space: nowrap;
}

.resource-link {
    display: inline-flex;
    align-items: center;
    gap: 0.3rem;
    color: var(--color-accent-primary);
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 500;
    transition: all var(--transition-fast);
    padding: 0.25rem 0.5rem;
    border-radius: var(--radius-sm);
}

.resource-link:hover {
    color: var(--color-accent-secondary);
    background: rgba(99, 102, 241, 0.1);
}

.resource-link svg {
    opacity: 0.7;
    transition: transform var(--transition-fast);
}

.resource-link:hover svg {
    transform: translate(2px, -2px);
}

.resource-name {
    font-family: var(--font-mono);
}

.ai-tools {
    display: flex;
    gap: var(--space-xs);
    flex-wrap: wrap;
}

.ai-badge {
    font-size: 0.8rem;
    padding: 0.35rem 0.75rem;
    border-radius: var(--radius-sm);
    font-weight: 600;
    transition: all var(--transition-base);
    cursor: default;
}

.ai-badge.gemini {
    background: linear-gradient(135deg, #4285f4 0%, #8ab4f8 100%);
    color: white;
    box-shadow: 0 2px 8px rgba(66, 133, 244, 0.3);
}

.ai-badge.gemini:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(66, 133, 244, 0.4);
}

.ai-badge.chatgpt {
    background: linear-gradient(135deg, #10a37f 0%, #1a7f64 100%);
    color: white;
    box-shadow: 0 2px 8px rgba(16, 163, 127, 0.3);
}

.ai-badge.chatgpt:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(16, 163, 127, 0.4);
}

.github-link {
    display: inline-flex;
    align-items: center;
    gap: var(--space-xs);
    padding: 0.75rem 1.5rem;
    background: rgba(99, 102, 241, 0.1);
    border: 1px solid rgba(99, 102, 241, 0.3);
    border-radius: var(--radius-md);
    color: var(--color-text-primary);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.95rem;
    transition: all var(--transition-base);
    margin-bottom: var(--space-lg);
}

.github-link:hover {
    background: rgba(99, 102, 241, 0.2);
    border-color: var(--color-accent-primary);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(99, 102, 241, 0.3);
}

.github-link svg {
    transition: transform var(--transition-base);
}

.github-link:hover svg {
    transform: rotate(360deg);
}

.header-stats {
    display: flex;
    gap: var(--space-md);
    justify-content: center;
    flex-wrap: wrap;
}

.stat-card {
    background: rgba(99, 102, 241, 0.1);
    border: 1px solid rgba(99, 102, 241, 0.3);
    border-radius: var(--radius-md);
    padding: var(--space-md) var(--space-lg);
    min-width: 100px;
    transition: all var(--transition-base);
}

.stat-card:hover {
    transform: translateY(-5px);
    border-color: var(--color-accent-primary);
    box-shadow: 0 8px 24px rgba(99, 102, 241, 0.3);
}

.stat-number {
    font-size: 2rem;
    font-weight: 700;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-label {
    font-size: 0.875rem;
    color: var(--color-text-secondary);
    text-transform: uppercase;
    letter-spacing: 1px;
}

/* ==================== Day Entries ==================== */
.day-entry {
    margin-bottom: var(--space-xl);
    animation: fadeInUp 0.8s ease;
    animation-fill-mode: both;
}

.day-entry:nth-child(1) { animation-delay: 0.1s; }
.day-entry:nth-child(2) { animation-delay: 0.2s; }
.day-entry:nth-child(3) { animation-delay: 0.3s; }

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.day-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--space-sm);
    margin-bottom: var(--space-md);
    padding: var(--space-md) var(--space-lg);
    background: var(--gradient-card);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(99, 102, 241, 0.2);
    border-radius: var(--radius-lg);
    position: relative;
    overflow: hidden;
}

.day-header::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.1), transparent);
    transition: left 0.5s;
}

.day-header:hover::before {
    left: 100%;
}

.day-badge {
    display: flex;
    gap: var(--space-sm);
    align-items: center;
}

.day-number {
    font-size: 1.5rem;
    font-weight: 700;
    background: var(--gradient-secondary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.day-status {
    font-size: 0.75rem;
    padding: 0.25rem 0.75rem;
    border-radius: 12px;
    background: var(--color-accent-success);
    color: var(--color-bg-primary);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.day-date {
    font-size: 1rem;
    color: var(--color-text-secondary);
    font-weight: 500;
}

/* ==================== Entry Content ==================== */
.entry-content {
    background: var(--color-bg-card);
    backdrop-filter: blur(20px);
    border: 1px solid rgba(99, 102, 241, 0.15);
    border-radius: var(--radius-lg);
    padding: var(--space-lg);
    box-shadow: var(--shadow-md);
}

.section-title {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: var(--space-md);
    display: flex;
    align-items: center;
    gap: var(--space-xs);
    color: var(--color-text-primary);
}

/* ==================== Topics Grid ==================== */
.topics-section {
    margin-bottom: var(--space-xl);
}

.topics-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: var(--space-md);
}

.topic-card {
    background: rgba(99, 102, 241, 0.05);
    border: 1px solid rgba(99, 102, 241, 0.2);
    border-radius: var(--radius-md);
    padding: var(--space-md);
    transition: all var(--transition-base);
    cursor: pointer;
    position: relative;
    overflow: hidden;
}

.topic-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 3px;
    background: var(--gradient-primary);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform var(--transition-base);
}

.topic-card:hover::before {
    transform: scaleX(1);
}

.topic-card:hover {
    transform: translateY(-5px);
    background: var(--color-bg-card-hover);
    border-color: var(--color-accent-primary);
    box-shadow: 0 8px 24px rgba(99, 102, 241, 0.2);
}

.topic-icon {
    font-size: 2rem;
    margin-bottom: var(--space-sm);
    display: block;
}

.topic-card h4 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: var(--space-xs);
    color: var(--color-text-primary);
}

.topic-card p {
    font-size: 0.9rem;
    color: var(--color-text-secondary);
    line-height: 1.5;
}

.needs-review {
    color: var(--color-accent-warning) !important;
    font-weight: 500;
}

/* ==================== Exercises Section ==================== */
.exercises-section {
    margin-top: var(--space-xl);
}

.exercise-card {
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.08) 0%, rgba(139, 92, 246, 0.08) 100%);
    border: 1px solid rgba(139, 92, 246, 0.3);
    border-radius: var(--radius-md);
    padding: var(--space-lg);
    margin-bottom: var(--space-md);
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
}

.exercise-card::after {
    pointer-events: none;
    content: '';
    position: absolute;
    top: -50%;
    right: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(139, 92, 246, 0.1) 0%, transparent 70%);
    opacity: 0;
    transition: opacity var(--transition-slow);
}

.exercise-card:hover::after {
    opacity: 1;
}

.exercise-card:hover {
    transform: translateX(5px);
    border-color: var(--color-accent-secondary);
    box-shadow: 0 8px 32px rgba(139, 92, 246, 0.3);
}

.exercise-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--space-sm);
    margin-bottom: var(--space-sm);
}

.exercise-badge {
    font-size: 0.875rem;
    font-weight: 700;
    padding: 0.5rem 1rem;
    background: var(--gradient-primary);
    color: white;
    border-radius: var(--radius-sm);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.exercise-tech {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--color-accent-primary);
    background: rgba(99, 102, 241, 0.1);
    padding: 0.25rem 0.75rem;
    border-radius: var(--radius-sm);
}

.exercise-description {
    color: var(--color-text-secondary);
    line-height: 1.6;
    margin-bottom: var(--space-sm);
}

.exercise-link {
    font-family: var(--font-mono);
    font-size: 0.875rem;
    color: var(--color-accent-tertiary);
    font-weight: 500;
    display: inline-block;
    padding: var(--space-xs) var(--space-sm);
    background: rgba(236, 72, 153, 0.1);
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
}

.exercise-anchor {
  position: absolute;
  inset: 0;
}

.exercise-link:hover {
    background: rgba(236, 72, 153, 0.2);
}

/* ==================== Footer ==================== */
.journal-footer {
    margin-top: var(--space-2xl);
    text-align: center;
    padding: var(--space-xl);
    background: var(--gradient-card);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(99, 102, 241, 0.2);
    border-radius: var(--radius-xl);
}

.footer-content p {
    color: var(--color-text-secondary);
    margin-bottom: var(--space-xs);
}

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

/* ==================== Responsive Design ==================== */
@media (max-width: 768px) {
    :root {
        --space-xl: 2rem;
        --space-2xl: 3rem;
    }

    .container {
        padding: var(--space-md);
    }

    .main-title {
        flex-direction: column;
        gap: var(--space-xs);
    }

    .resources-section {
        padding: var(--space-sm);
    }

    .resource-item {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.5rem;
    }

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

    .day-header {
        flex-direction: column;
        align-items: flex-start;
    }

    .header-stats {
        width: 100%;
    }

    .stat-card {
        flex: 1;
        min-width: initial;
    }
}

/* ==================== Scrollbar Styling ==================== */
::-webkit-scrollbar {
    width: 10px;
}

::-webkit-scrollbar-track {
    background: var(--color-bg-secondary);
}

::-webkit-scrollbar-thumb {
    background: linear-gradient(180deg, var(--color-accent-primary), var(--color-accent-secondary));
    border-radius: 5px;
}

::-webkit-scrollbar-thumb:hover {
    background: linear-gradient(180deg, var(--color-accent-secondary), var(--color-accent-tertiary));
}

/* ==================== Selection ==================== */
::selection {
    background: var(--color-accent-primary);
    color: white;
}