:root {
    --bg-base: #02040a;
    --bg-surface: #0e1117;
    --bg-card: rgba(22, 27, 34, 0.6);
    --border-color: rgba(48, 54, 61, 0.8);
    --border-hover: rgba(139, 148, 158, 0.5);
    
    --text-primary: #e6edf3;
    --text-secondary: #848d97;
    --text-muted: #6e7681;
    
    --accent-color: #39d353;
    --accent-glow: rgba(57, 211, 83, 0.3);
    
    /* Heatmap Colors */
    --color-calendar-graph-day-bg: #161b22;
    --color-calendar-graph-day-L1-bg: #0e4429;
    --color-calendar-graph-day-L2-bg: #006d32;
    --color-calendar-graph-day-L3-bg: #26a641;
    --color-calendar-graph-day-L4-bg: #39d353;
    
    /* Gradients */
    --gradient-primary: linear-gradient(135deg, #26a641, #39d353);
    --gradient-streak: linear-gradient(135deg, #f78166, #e34c26);
    
    --radius-sm: 6px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --radius-full: 9999px;
    
    --shadow-sm: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-md: 0 10px 15px -3px rgba(0, 0, 0, 0.5), 0 4px 6px -2px rgba(0, 0, 0, 0.25);
    --shadow-glow: 0 0 20px var(--accent-glow);
    
    --transition-fast: 0.15s ease;
    --transition-normal: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
    background-color: var(--bg-base);
    color: var(--text-primary);
    line-height: 1.5;
    min-height: 100vh;
    display: flex;
    justify-content: center;
    background-image: 
        radial-gradient(circle at 15% 50%, rgba(38, 166, 65, 0.05) 0%, transparent 50%),
        radial-gradient(circle at 85% 30%, rgba(57, 211, 83, 0.03) 0%, transparent 50%);
}

.app-container {
    width: 100%;
    max-width: 1000px;
    padding: 2rem;
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

/* Header */
.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-bottom: 2rem;
    border-bottom: 1px solid var(--border-color);
    flex-wrap: wrap;
    gap: 1.5rem;
}

.logo {
    font-size: 1.75rem;
    font-weight: 800;
    letter-spacing: -0.05em;
    color: var(--text-primary);
}

.logo span {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.search-container {
    display: flex;
    gap: 0.5rem;
    position: relative;
    width: 100%;
    max-width: 350px;
}

.search-container input {
    width: 100%;
    padding: 0.75rem 1rem 0.75rem 2.5rem;
    border-radius: var(--radius-full);
    background-color: var(--bg-surface);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    font-family: 'Inter', sans-serif;
    font-size: 0.95rem;
    outline: none;
    transition: var(--transition-normal);
}

.search-container input:focus {
    border-color: var(--accent-color);
    box-shadow: 0 0 0 2px rgba(57, 211, 83, 0.2);
    background-color: var(--bg-card);
}

.search-container input::placeholder {
    color: var(--text-muted);
}

.search-container::before {
    content: '@';
    position: absolute;
    left: 1rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-muted);
    font-weight: 500;
}

#search-btn {
    background: var(--gradient-primary);
    color: #fff;
    border: none;
    border-radius: var(--radius-full);
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: var(--transition-fast);
    box-shadow: var(--shadow-sm);
}

#search-btn:hover {
    transform: translateY(-2px) scale(1.05);
    box-shadow: var(--shadow-glow);
}

#search-btn:active {
    transform: translateY(0) scale(0.95);
}

/* Into State */
.intro-state {
    text-align: center;
    padding: 4rem 2rem;
    color: var(--text-secondary);
    max-width: 500px;
    margin: 0 auto;
}

.intro-icon {
    font-size: 4rem;
    margin-bottom: 1.5rem;
    animation: bounce-gentle 2s infinite ease-in-out;
}

.intro-state h2 {
    color: var(--text-primary);
    margin-bottom: 1rem;
    font-size: 1.5rem;
}

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

/* Main Content */
.main-content {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

/* Profile Section */
.profile-section {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

.avatar {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    border: 3px solid rgba(57, 211, 83, 0.2);
    box-shadow: var(--shadow-sm);
    object-fit: cover;
}

.user-info h2 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 0.25rem;
}

.login {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 1rem;
    transition: var(--transition-fast);
}

.login:hover {
    color: var(--accent-color);
}

/* Stats Grid */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
}

.stat-card {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 1.5rem;
    display: flex;
    align-items: center;
    gap: 1rem;
    transition: var(--transition-normal);
    backdrop-filter: blur(10px);
}

.stat-card:hover {
    transform: translateY(-4px);
    border-color: var(--border-hover);
    box-shadow: var(--shadow-md);
}

.stat-card.highlight {
    border-color: rgba(57, 211, 83, 0.3);
    background: linear-gradient(180deg, rgba(57, 211, 83, 0.05) 0%, rgba(22, 27, 34, 0.6) 100%);
}

.stat-card.highlight:hover {
    box-shadow: var(--shadow-glow);
    border-color: var(--accent-color);
}

.stat-icon {
    font-size: 2rem;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 60px;
    height: 60px;
    border-radius: var(--radius-full);
    background: rgba(255, 255, 255, 0.05);
}

.streak-icon { background: rgba(247, 129, 102, 0.1); }
.longest-icon { background: rgba(210, 168, 255, 0.1); }
.total-icon { background: rgba(56, 139, 253, 0.1); }

.stat-content h3 {
    font-size: 0.85rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    font-weight: 600;
    margin-bottom: 0.25rem;
}

.stat-value {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--text-primary);
}

/* Heatmap Section */
.heatmap-section {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 1.5rem;
    backdrop-filter: blur(10px);
}

.heatmap-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
}

.heatmap-header h3 {
    font-size: 1.1rem;
    font-weight: 600;
}

.year-selector select {
    background: var(--bg-surface);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    padding: 0.4rem 0.8rem;
    border-radius: var(--radius-full);
    font-size: 0.85rem;
    font-family: inherit;
    cursor: pointer;
    outline: none;
    transition: var(--transition-fast);
}

.year-selector select:hover {
    border-color: var(--border-hover);
}

.heatmap-scroll-container {
    overflow-x: auto;
    padding-bottom: 1rem;
    /* Custom scrollbar */
    scrollbar-width: thin;
    scrollbar-color: var(--border-hover) transparent;
}

.heatmap-scroll-container::-webkit-scrollbar {
    height: 6px;
}
.heatmap-scroll-container::-webkit-scrollbar-track {
    background: transparent;
}
.heatmap-scroll-container::-webkit-scrollbar-thumb {
    background-color: var(--border-color);
    border-radius: 20px;
}

.heatmap-container {
    display: inline-grid;
    grid-template-rows: repeat(7, 12px);
    grid-auto-flow: column;
    grid-auto-columns: 12px;
    gap: 4px;
    min-width: max-content;
}

.heatmap-day {
    width: 12px;
    height: 12px;
    border-radius: 2px;
    outline: 1px solid rgba(27, 31, 35, 0.06);
    outline-offset: -1px;
    transition: transform 0.1s;
    cursor: pointer;
    position: relative;
}

.heatmap-day:hover {
    transform: scale(1.2);
    z-index: 10;
    box-shadow: 0 0 10px rgba(0,0,0,0.5);
}

/* Tooltip for heatmap */
.heatmap-day::after {
    content: attr(data-tooltip);
    position: absolute;
    bottom: 100%;
    left: 50%;
    transform: translateX(-50%) translateY(-8px);
    background: #000;
    color: #fff;
    padding: 4px 8px;
    border-radius: 4px;
    font-size: 12px;
    white-space: nowrap;
    opacity: 0;
    pointer-events: none;
    z-index: 20;
    transition: opacity 0.2s;
}

.heatmap-day:hover::after {
    opacity: 1;
}

.heatmap-day[data-level="0"] { background-color: var(--color-calendar-graph-day-bg); }
.heatmap-day[data-level="1"] { background-color: var(--color-calendar-graph-day-L1-bg); }
.heatmap-day[data-level="2"] { background-color: var(--color-calendar-graph-day-L2-bg); }
.heatmap-day[data-level="3"] { background-color: var(--color-calendar-graph-day-L3-bg); }
.heatmap-day[data-level="4"] { background-color: var(--color-calendar-graph-day-L4-bg); }

.heatmap-legend {
    display: flex;
    align-items: center;
    justify-content: flex-end;
    gap: 4px;
    margin-top: 1rem;
    font-size: 0.75rem;
    color: var(--text-muted);
}

.legend-text {
    margin: 0 4px;
}

.legend-box {
    width: 10px;
    height: 10px;
    border-radius: 2px;
}

.legend-box.level-0 { background-color: var(--color-calendar-graph-day-bg); }
.legend-box.level-1 { background-color: var(--color-calendar-graph-day-L1-bg); }
.legend-box.level-2 { background-color: var(--color-calendar-graph-day-L2-bg); }
.legend-box.level-3 { background-color: var(--color-calendar-graph-day-L3-bg); }
.legend-box.level-4 { background-color: var(--color-calendar-graph-day-L4-bg); }

/* Loading & Error States */
.loading-state, .error-message {
    text-align: center;
    padding: 3rem;
    background-color: var(--bg-card);
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
}

.error-message {
    border-color: rgba(248, 81, 73, 0.4);
    color: #f85149;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
}

.spinner {
    width: 40px;
    height: 40px;
    border: 3px solid rgba(57, 211, 83, 0.2);
    border-top-color: var(--accent-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto 1rem;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* Animations */
.fade-in {
    opacity: 0;
    transform: translateY(15px);
    animation: fadeIn 0.5s forwards ease-out;
}

.fade-in.delay-1 { animation-delay: 0.1s; }
.fade-in.delay-2 { animation-delay: 0.2s; }

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

/* Responsive */
@media (max-width: 640px) {
    .header {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .search-container {
        max-width: 100%;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
}