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

:root {
    --primary: #2c3e50;
    --secondary: #34495e;
    --accent: #3498db;
    --accent-hover: #2980b9;
    --bg: #f8f9fa;
    --card-bg: #fff;
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.08);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.12);
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

body {
    font-family: 'Roboto', sans-serif;
    background-color: var(--bg);
    color: var(--primary);
    margin: 0;
    display: flex;
    overflow-x: hidden;
    line-height: 1.6;
}

/* Mobile Menu Toggle Button */
.menu-toggle {
    display: none;
    position: fixed;
    top: 20px;
    left: 20px;
    z-index: 1001;
    background: var(--accent);
    border: none;
    border-radius: 8px;
    width: 25px;
    height: 25px;
    cursor: pointer;
    box-shadow: var(--shadow-md);
    transition: var(--transition);
}

.menu-toggle:hover {
    background: var(--accent-hover);
    transform: scale(1.05);
}

.menu-toggle span {
    display: block;
    width: 15px;
    height: 3px;
    background: white;
    margin: 5px auto;
    border-radius: 2px;
    transition: var(--transition);
}

/* Sidebar */
.sidebar {
    width: 250px;
    background: linear-gradient(180deg, var(--primary) 0%, var(--secondary) 100%);
    color: #fff;
    height: 100vh;
    position: fixed;
    padding-top: 20px;
    box-shadow: 2px 0 15px rgba(0, 0, 0, 0.15);
    z-index: 1000;
    transition: var(--transition);
    overflow-y: auto;
}

.sidebar h2 {
    text-align: center;
    font-size: 1.3rem;
    margin-bottom: 30px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.2);
    padding-bottom: 20px;
    font-weight: 500;
    letter-spacing: 0.5px;
}

.nav-link {
    display: block;
    padding: 15px 25px;
    color: #ecf0f1;
    text-decoration: none;
    transition: var(--transition);
    border-left: 4px solid transparent;
    font-weight: 400;
}

.nav-link:hover {
    background: rgba(255, 255, 255, 0.1);
    border-left: 4px solid var(--accent);
    padding-left: 30px;
}

/* Main Content */
.main-content {
    margin-left: 250px;
    padding: 40px;
    width: 100%;
    box-sizing: border-box;
    transition: var(--transition);
}

.header {
    margin-bottom: 40px;
    animation: fadeInDown 0.6s ease-out;
}

@keyframes fadeInDown {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }

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

.header h1 {
    margin: 0;
    font-size: 2.5rem;
    color: var(--secondary);
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary), var(--accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.date {
    color: #7f8c8d;
    font-size: 0.95rem;
    margin-top: 8px;
    font-weight: 300;
}

/* Grid Layout */
.grid-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 20px;
    margin-bottom: 40px;
}

/* Cards */
.card {
    background: var(--card-bg);
    border-radius: 12px;
    box-shadow: var(--shadow-sm);
    overflow: hidden;
    transition: var(--transition);
    border: 1px solid rgba(0, 0, 0, 0.05);
}

.card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
}

.card-header {
    background: linear-gradient(135deg, var(--accent), var(--accent-hover));
    color: white;
    padding: 15px 20px;
    font-weight: 500;
    font-size: 1.1rem;
}

.card-body {
    padding: 25px;
    text-align: center;
}

.stat-value {
    font-size: 2.8rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--accent), #9b59b6);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 8px;
}

.stat-label {
    color: #95a5a6;
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 1.5px;
    font-weight: 500;
}

/* Section */
.section {
    background: white;
    border-radius: 12px;
    padding: 35px;
    margin-bottom: 40px;
    box-shadow: var(--shadow-sm);
    border: 1px solid rgba(0, 0, 0, 0.05);
    animation: fadeIn 0.6s ease-out;
}

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

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

.section-title {
    font-size: 1.6rem;
    margin-bottom: 25px;
    color: var(--secondary);
    border-left: 5px solid var(--accent);
    padding-left: 15px;
    font-weight: 600;
}

.two-cols {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 30px;
    align-items: start;
}

.explanation {
    background: linear-gradient(135deg, #e8f6f3, #d5f4e6);
    border-radius: 8px;
    padding: 20px;
    color: #16a085;
    font-size: 0.95rem;
    line-height: 1.7;
    border-left: 4px solid #16a085;
    box-shadow: var(--shadow-sm);
}

.explanation strong {
    color: #0e6655;
    display: block;
    margin-bottom: 10px;
    font-size: 1.05rem;
}

img {
    max-width: 100%;
    height: auto;
    border-radius: 8px;
    border: 1px solid #eee;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

img:hover {
    box-shadow: var(--shadow-md);
    transform: scale(1.02);
}

h4 {
    color: var(--secondary);
    font-size: 1.2rem;
    margin-bottom: 15px;
    font-weight: 600;
}

table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 20px;
    font-size: 0.9rem;
    overflow-x: auto;
    display: block;
}

table thead,
table tbody {
    display: table;
    width: 100%;
    table-layout: fixed;
}

th {
    background: linear-gradient(135deg, #f8f9fa, #e9ecef);
    color: var(--secondary);
    font-weight: 600;
    text-align: left;
    padding: 14px 12px;
    position: sticky;
    top: 0;
    z-index: 10;
}

td {
    padding: 14px 12px;
    border-bottom: 1px solid #f0f0f0;
    transition: background 0.2s ease;
}

tr:hover td {
    background: #f8f9fa;
}

tr:last-child td {
    border-bottom: none;
}

/* Responsive Design - Tablet */
@media screen and (max-width: 1024px) {
    .main-content {
        padding: 30px;
    }

    .header h1 {
        font-size: 2rem;
    }

    .grid-container {
        grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
        gap: 15px;
    }

    .two-cols {
        grid-template-columns: 1fr;
        gap: 20px;
    }

    .section {
        padding: 25px;
    }
}

/* Responsive Design - Mobile */
@media screen and (max-width: 768px) {
    .menu-toggle {
        display: flex;
        align-items: center;
        justify-content: center;
    }

    .sidebar {
        transform: translateX(-100%);
        width: 280px;
    }

    .sidebar.active {
        transform: translateX(0);
    }

    .main-content {
        margin-left: 0;
        padding: 90px 20px 20px 20px;
        width: 100%;
    }

    .header h1 {
        font-size: 1.75rem;
        line-height: 1.3;
    }

    .date {
        font-size: 0.85rem;
    }

    .grid-container {
        grid-template-columns: 1fr;
        gap: 15px;
    }

    .card-body {
        padding: 20px;
    }

    .stat-value {
        font-size: 2.2rem;
    }

    .stat-label {
        font-size: 0.8rem;
    }

    .section {
        padding: 20px;
        border-radius: 10px;
    }

    .section-title {
        font-size: 1.3rem;
        margin-bottom: 20px;
    }

    h4 {
        font-size: 1.1rem;
    }

    table {
        font-size: 0.85rem;
    }

    th,
    td {
        padding: 10px 8px;
    }

    .explanation {
        padding: 15px;
        font-size: 0.9rem;
    }

    .two-cols {
        grid-template-columns: 1fr;
    }
}

/* Extra Small Mobile */
@media screen and (max-width: 480px) {
    .main-content {
        padding: 80px 15px 15px 15px;
    }

    .header h1 {
        font-size: 1.5rem;
    }

    .stat-value {
        font-size: 2rem;
    }

    .section {
        padding: 15px;
    }

    .section-title {
        font-size: 1.2rem;
        padding-left: 12px;
    }

    table {
        font-size: 0.8rem;
    }

    th,
    td {
        padding: 8px 6px;
    }

    .sidebar {
        width: 100%;
    }

    .menu-toggle {
        width: 15px;
        height: 15px;
    }
}

/* Smooth Scrolling */
html {
    scroll-behavior: smooth;
}

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: #f1f1f1;
}

::-webkit-scrollbar-thumb {
    background: var(--accent);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--accent-hover);
}