/* ==========================================================================
   assets/css/main.css (Priority 1.3)
   Core Structural Styles for the Statistical Course Platform
   ========================================================================== */

/* --- Root Variables & Reset --- */
:root {
    /* Timing & Animation */
    --transition-speed: 0.3s;
}

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

body {
    font-family: 'Open Sans', sans-serif; /* Fallback font */
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* --- Core Layout & Container --- */
.container {
    max-width: 1200px;
    width: 90%;
    margin: 0 auto;
}

main {
    flex-grow: 1; /* Ensures footer stays at the bottom */
}

/* --- Typography Structure (Un-themed) --- */
h1, h2, h3, h4, h5, h6 {
    font-family: 'Roboto Slab', serif; /* Structural font family */
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 1rem;
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.2rem; }

p {
    margin-bottom: 1rem;
    font-size: 1rem;
}

a {
    text-decoration: none;
    transition: all var(--transition-speed) ease;
}

ul, ol {
    padding-left: 20px;
    margin-bottom: 1rem;
}

/* --- Header & Footer Structure --- */
.header {
    padding: 2rem 0;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

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

.footer {
    padding: 2rem 0;
    text-align: center;
}

/* --- Reusable Card & Grid Components --- */
.card {
    background: white;
    border-radius: 10px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    transition: transform var(--transition-speed) ease, box-shadow var(--transition-speed) ease;
    overflow: hidden;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
}

.grid-system {
    display: grid;
    gap: 2rem;
}

/* Responsive Grid Columns */
.grid-cols-2 { grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); }
.grid-cols-3 { grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); }
.grid-cols-4 { grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); }

/* --- Buttons & Badges --- */
.button {
    display: inline-block;
    padding: 0.8rem 1.8rem;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    font-size: 1rem;
    border: none;
    cursor: pointer;
    transition: all var(--transition-speed) ease;
}

.badge {
    display: inline-block;
    padding: 0.5rem 1.5rem;
    border-radius: 25px;
    font-weight: 600;
    font-size: 0.9rem;
}

/* --- Assessment Dashboard Styles --- */
.assessments-section {
    padding: 4rem 0;
}

.assessments-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.assessment-card {
    background: white;
    border-radius: 15px;
    overflow: hidden;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    transition: all var(--transition-speed) ease;
    border: 3px solid transparent;
}

.assessment-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
}

.assessment-header {
    padding: 2rem;
    color: white;
    position: relative;
}

.assessment-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
    display: block;
}

.assessment-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.assessment-details {
    opacity: 0.9;
    font-size: 0.9rem;
}

.assessment-content {
    padding: 2rem;
}

.assessment-description {
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

.quiz-status {
    display: inline-block;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
}

.btn-quiz {
    display: inline-block;
    color: white;
    padding: 0.8rem 2rem;
    border-radius: 25px;
    text-decoration: none;
    font-weight: 600;
    transition: all var(--transition-speed) ease;
    width: 100%;
    text-align: center;
}

.btn-quiz:hover {
    transform: translateY(-2px);
    color: white;
}

/* --- Practical Sessions Dashboard Styles --- */
.practical-sessions-section {
    padding: 4rem 0;
}

.sessions-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.session-card {
    background: white;
    border-radius: 15px;
    overflow: hidden;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    transition: all var(--transition-speed) ease;
    border: 3px solid transparent;
}

.session-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
}

.session-header {
    padding: 2rem;
    color: white;
    position: relative;
}

.session-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
    display: block;
}

.session-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.session-duration {
    opacity: 0.9;
    font-size: 0.9rem;
}

.session-content {
    padding: 2rem;
}

.session-description {
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

.session-components {
    list-style: none;
    padding: 0;
    margin-bottom: 2rem;
}

.session-components li {
    padding: 0.3rem 0;
    display: flex;
    align-items: center;
}

.btn-session {
    display: inline-block;
    color: white;
    padding: 0.8rem 2rem;
    border-radius: 25px;
    text-decoration: none;
    font-weight: 600;
    transition: all var(--transition-speed) ease;
    width: 100%;
    text-align: center;
}

.btn-session:hover {
    transform: translateY(-2px);
    color: white;
}

/* --- Content Styling for Articles (like course-guide.html) --- */
.content-article {
    background: white;
    padding: 2rem 3rem;
    border-radius: 10px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
}

.content-section {
    margin-bottom: 3rem;
}

.section-title-underline {
    display: inline-block;
    border-bottom: 3px solid; /* Color will be from theme */
    padding-bottom: 0.5rem;
    margin-bottom: 1.5rem;
}

.key-principles {
    display: flex;
    justify-content: space-around;
    gap: 2rem;
    text-align: center;
    margin-top: 2rem;
}

.principle-card i {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.module-summary-grid {
    display: grid;
    gap: 1.5rem;
    grid-template-columns: 1fr 1fr;
}

.module-summary-card {
    border-radius: 8px;
    overflow: hidden;
    border: 1px solid; /* Color from theme */
}

.module-summary-header {
    padding: 1rem 1.5rem;
}

.module-summary-header span {
    font-size: 0.9rem;
    font-weight: 600;
}

.module-summary-body {
    padding: 1.5rem;
}

.checklist {
    list-style-type: none;
    padding-left: 0;
}

.checklist li {
    position: relative;
    padding-left: 25px;
    margin-bottom: 0.5rem;
}

.checklist li::before {
    content: '✅';
    position: absolute;
    left: 0;
    top: 0;
}

/* --- Media Queries for Responsiveness --- */
@media (max-width: 992px) {
    h1 { font-size: 2.2rem; }
    h2 { font-size: 1.8rem; }
    .content-article { padding: 2rem; }
}

@media (max-width: 768px) {
    .grid-cols-2, .grid-cols-3, .grid-cols-4, .module-summary-grid {
        grid-template-columns: 1fr;
    }
    .key-principles {
        flex-direction: column;
    }
    .assessments-grid, .sessions-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 576px) {
    .assessment-card, .session-card {
        margin: 0 10px;
    }
    .assessment-content, .session-content {
        padding: 1.5rem;
    }
    .assessment-header, .session-header {
        padding: 1.5rem;
    }
}