@import url('https://fonts.googleapis.com/css2?family=DM+Sans:wght@400;500;700&display=swap');
@import url('https://fonts.googleapis.com/icon?family=Material+Icons');

/* ========== RESET & BASE STYLES ========== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #708090;
    --accent-color: #0000ff;
    --text-color: #2c3e50;
    --bg-light: #f8f9fa;
    --bg-white: #ffffff;
    --border-color: #e0e0e0;
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'DM Sans', sans-serif;
    line-height: 1.7;
    color: var(--text-color);
    background-color: var(--bg-light);
    font-size: 18px;
}

/* ========== TYPOGRAPHY ========== */
h1 {
    font-size: 2.75rem !important;
    font-weight: 700 !important;
    line-height: 1.2 !important;
    margin-bottom: 1.5rem !important;
    color: var(--text-color) !important;
}

h2 {
    font-size: 2.25rem !important;
    font-weight: 700 !important;
    line-height: 1.3 !important;
    margin-top: 3rem !important;
    margin-bottom: 1.5rem !important;
    color: var(--primary-color) !important;
}

h3 {
    font-size: 1.75rem !important;
    font-weight: 600 !important;
    line-height: 1.4 !important;
    margin-top: 2rem !important;
    margin-bottom: 1rem !important;
    color: var(--text-color) !important;
}

p {
    font-size: 18px !important;
    line-height: 1.8 !important;
    margin-bottom: 1.5rem !important;
    color: var(--text-color) !important;
}

strong {
    font-weight: 700;
    color: var(--primary-color);
}

em {
    font-style: italic;
    color: var(--accent-color);
}

/* ========== NAVIGATION ========== */
.navbar {
    background-color: var(--bg-white) !important;
    box-shadow: var(--shadow) !important;
    padding: 1rem 0 !important;
    position: sticky;
    top: 0;
    z-index: 1000;
}

.navbar-brand {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color) !important;
}

.navbar-brand img {
    width: 40px;
    height: 40px;
}

.navbar-menu {
    list-style: none !important;
}

.navbar-menu::before,
.navbar-menu::after {
    display: none !important;
}

.navbar-item {
    list-style: none !important;
    font-size: 1rem;
    font-weight: 500;
    color: var(--text-color) !important;
    transition: color 0.3s ease;
}

.navbar-item::before,
.navbar-item::after {
    display: none !important;
}

.navbar-item:hover,
.navbar-item:focus {
    color: var(--accent-color) !important;
    background-color: transparent !important;
}

.navbar-burger {
    color: var(--primary-color);
}

.cta-button {
    background-color: transparent !important;
    border: 2px solid var(--accent-color) !important;
    color: var(--accent-color) !important;
    padding: 0.65rem 1.5rem !important;
    font-size: 1rem !important;
    font-weight: 600 !important;
    border-radius: 6px !important;
    transition: all 0.3s ease !important;
    text-decoration: none !important;
    display: inline-block !important;
    white-space: nowrap !important;
    text-align: center !important;
}

.cta-button:hover {
    background-color: var(--accent-color) !important;
    color: var(--bg-white) !important;
    transform: translateY(-2px);
}

/* ========== HERO SECTION ========== */
.hero {
    background: linear-gradient(135deg, #708090 0%, #5a6d7f 100%) !important;
    padding: 5rem 1.5rem !important;
    text-align: center !important;
}

.hero h1 {
    color: var(--bg-white) !important;
    font-size: 3rem !important;
    margin-bottom: 1.5rem !important;
}

.hero p {
    color: var(--bg-white) !important;
    font-size: 1.25rem !important;
    max-width: 800px !important;
    margin: 0 auto 2rem !important;
}

.hero .cta-button {
    border-color: var(--bg-white) !important;
    color: var(--bg-white) !important;
    font-size: 1.1rem !important;
    padding: 0.85rem 2rem !important;
}

.hero .cta-button:hover {
    background-color: var(--bg-white) !important;
    color: var(--primary-color) !important;
}

/* ========== TABLE OF CONTENTS ========== */
.table-of-contents {
    background-color: var(--bg-white);
    padding: 2rem;
    border-radius: 8px;
    box-shadow: var(--shadow);
    margin: 2rem 0;
}

.toc-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    justify-content: center;
}

.toc-button {
    background-color: transparent !important;
    border: 2px solid var(--primary-color) !important;
    color: var(--primary-color) !important;
    padding: 0.75rem 1.5rem !important;
    font-size: 1rem !important;
    font-weight: 500 !important;
    border-radius: 6px !important;
    transition: all 0.3s ease !important;
    text-decoration: none !important;
    display: inline-block !important;
    white-space: nowrap !important;
}

.toc-button:hover {
    background-color: var(--primary-color) !important;
    color: var(--bg-white) !important;
    transform: translateY(-2px);
}

/* ========== SECTIONS ========== */
section {
    padding: 3rem 0;
}

.section-card {
    background-color: var(--bg-white);
    border-radius: 8px;
    padding: 2.5rem;
    margin-bottom: 2rem;
    box-shadow: var(--shadow);
}

/* ========== LISTS ========== */
ul, ol {
    list-style: none !important;
    margin-left: 0 !important;
    padding-left: 0 !important;
    margin-bottom: 1.5rem !important;
}

.content ul li,
.section-card ul li {
    position: relative;
    padding-left: 2rem;
    margin-bottom: 1rem;
    font-size: 18px;
    line-height: 1.7;
}

.content ul li::before,
.section-card ul li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0.6rem;
    width: 12px;
    height: 12px;
    background-color: var(--accent-color);
    border-radius: 50%;
}

.content ol li,
.section-card ol li {
    position: relative;
    padding-left: 2.5rem;
    margin-bottom: 1rem;
    font-size: 18px;
    line-height: 1.7;
    counter-increment: item;
}

.content ol,
.section-card ol {
    counter-reset: item;
}

.content ol li::before,
.section-card ol li::before {
    content: counter(item);
    position: absolute;
    left: 0;
    top: 0;
    width: 28px;
    height: 28px;
    background-color: var(--accent-color);
    color: var(--bg-white);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 14px;
}

/* ========== IMAGES ========== */
picture {
    display: block;
    margin: 2rem 0;
}

img {
    max-width: 100%;
    height: auto;
    border-radius: 8px;
    box-shadow: var(--shadow);
}

/* ========== TABLES ========== */
.table-container {
    overflow-x: auto;
    margin: 2rem 0;
    border-radius: 8px;
    box-shadow: var(--shadow);
}

table {
    width: 100%;
    border-collapse: collapse;
    background-color: var(--bg-white);
    font-size: 18px;
}

thead {
    background-color: var(--primary-color);
    color: var(--bg-white);
}

th {
    padding: 1.25rem;
    text-align: left;
    font-weight: 700;
    font-size: 1.1rem;
}

td {
    padding: 1.25rem;
    border-bottom: 1px solid var(--border-color);
}

tbody tr:hover {
    background-color: var(--bg-light);
}

/* ========== CARDS ========== */
.card {
    background-color: var(--bg-white);
    border-radius: 8px;
    padding: 2rem;
    margin-bottom: 1.5rem;
    box-shadow: var(--shadow);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
    transform: translateY(-4px);
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.15);
}

.card-icon {
    color: var(--accent-color);
    font-size: 3rem;
    margin-bottom: 1rem;
}

/* ========== FOOTER ========== */
footer {
    background-color: var(--primary-color);
    color: var(--bg-white);
    padding: 3rem 1.5rem 1.5rem;
    margin-top: 4rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h3 {
    color: var(--bg-white) !important;
    font-size: 1.25rem !important;
    margin-bottom: 1rem !important;
}

.footer-section ul {
    list-style: none !important;
}

.footer-section ul::before,
.footer-section ul::after {
    display: none !important;
}

.footer-section li {
    list-style: none !important;
    margin-bottom: 0.75rem;
    padding-left: 0 !important;
}

.footer-section li::before,
.footer-section li::after {
    display: none !important;
}

.footer-section a {
    color: var(--bg-white);
    text-decoration: none;
    font-size: 1rem;
    transition: color 0.3s ease;
}

.footer-section a:hover {
    color: var(--accent-color);
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.2);
    font-size: 0.95rem;
}

/* ========== ICONS ========== */
.material-icons {
    vertical-align: middle;
    font-size: 1.5rem;
    color: var(--accent-color);
}

/* ========== RESPONSIVE DESIGN ========== */
@media screen and (max-width: 1024px) {
    h1 {
        font-size: 2.25rem !important;
    }

    h2 {
        font-size: 1.875rem !important;
    }

    h3 {
        font-size: 1.5rem !important;
    }

    .hero h1 {
        font-size: 2.5rem !important;
    }
}

@media screen and (max-width: 768px) {
    body {
        font-size: 16px;
    }

    h1 {
        font-size: 1.875rem !important;
    }

    h2 {
        font-size: 1.625rem !important;
    }

    h3 {
        font-size: 1.375rem !important;
    }

    p, .content ul li, .section-card ul li, .content ol li, .section-card ol li {
        font-size: 16px !important;
    }

    .hero {
        padding: 3rem 1.5rem !important;
    }

    .hero h1 {
        font-size: 2rem !important;
    }

    .hero p {
        font-size: 1.1rem !important;
    }

    .section-card {
        padding: 1.5rem;
    }

    .toc-buttons {
        flex-direction: column;
    }

    .toc-button {
        width: 100%;
        text-align: center;
    }

    .footer-content {
        grid-template-columns: 1fr;
    }

    table {
        font-size: 16px;
    }

    th, td {
        padding: 1rem;
    }
}

@media screen and (max-width: 480px) {
    h1 {
        font-size: 1.625rem !important;
    }

    h2 {
        font-size: 1.5rem !important;
    }

    h3 {
        font-size: 1.25rem !important;
    }

    .hero h1 {
        font-size: 1.75rem !important;
    }

    .navbar-brand {
        font-size: 1.25rem;
    }

    .navbar-brand img {
        width: 32px;
        height: 32px;
    }
}

/* ========== UTILITY CLASSES ========== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

.text-center {
    text-align: center;
}

.mt-2 {
    margin-top: 2rem;
}

.mb-2 {
    margin-bottom: 2rem;
}