/* ============================================
   ACADEMIC PORTFOLIO - MAIN STYLES
   Version: 2.0.0
   ============================================ */

/* ============================================
   GLOBAL VARIABLES & RESET
   ============================================ */
:root {
    /* Color Palette */
    --primary-navy: #1a365d;
    --primary-gray: #4a5568;
    --background: #f7fafc;
    --card-background: #ffffff;
    --accent: #8C1515; /* Default: Stanford Cardinal */
    --success: #48bb78;
    --warning: #ed8936;
    --danger: #f56565;
    --border-color: #e2e8f0;
    --text-muted: #718096;

    /* Typography */
    --font-heading: 'Playfair Display', Georgia, serif;
    --font-body: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Inter', sans-serif;
    --font-mono: 'Fira Code', 'Courier New', monospace;

    /* Layout */
    --sidebar-width: 280px;
    --content-max-width: 1200px;
    --card-padding: 24px;
    --border-radius: 8px;
    --transition-speed: 0.2s;

    /* Z-index layers */
    --z-base: 1;
    --z-dropdown: 100;
    --z-sticky: 200;
    --z-fixed: 300;
    --z-modal-backdrop: 1000;
    --z-modal: 1001;
    --z-popover: 1002;
    --z-tooltip: 1003;
    --z-notification: 2000;
}

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

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

/* ============================================
   TYPOGRAPHY
   ============================================ */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    color: var(--primary-navy);
    font-weight: 600;
    margin-bottom: 0.5em;
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }
h5 { font-size: 1.125rem; }
h6 { font-size: 1rem; }

p {
    margin-bottom: 1em;
}

a {
    color: var(--accent);
    text-decoration: none;
    transition: color var(--transition-speed);
}

a:hover {
    text-decoration: underline;
}

/* ============================================
   LAYOUT STRUCTURE
   ============================================ */
.app-container {
    display: flex;
    min-height: 100vh;
}

.sidebar {
    width: var(--sidebar-width);
    background: var(--primary-navy);
    color: white;
    padding: 2rem 0;
    position: fixed;
    height: 100vh;
    overflow-y: auto;
    z-index: var(--z-fixed);
}

.sidebar-logo {
    padding: 0 1.5rem 2rem;
    border-bottom: 1px solid rgba(255,255,255,0.1);
    margin-bottom: 2rem;
}

.sidebar-logo h2 {
    color: white;
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
}

.sidebar-logo p {
    font-size: 0.875rem;
    opacity: 0.8;
}

.sidebar-nav {
    list-style: none;
}

.sidebar-nav li {
    margin-bottom: 0.5rem;
}

.sidebar-nav a {
    display: flex;
    align-items: center;
    padding: 0.75rem 1.5rem;
    color: rgba(255,255,255,0.9);
    text-decoration: none;
    transition: all var(--transition-speed);
}

.sidebar-nav a:hover,
.sidebar-nav a.active {
    background: rgba(255,255,255,0.1);
    color: white;
    border-left: 4px solid var(--accent);
}

.sidebar-nav .icon {
    margin-right: 0.75rem;
    font-size: 1.25rem;
}

.main-content {
    margin-left: var(--sidebar-width);
    flex: 1;
    padding: 2rem;
    max-width: 100%;
}

.top-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    padding-bottom: 1rem;
    border-bottom: 2px solid var(--border-color);
}

.top-bar h1 {
    margin: 0;
}

.top-bar-actions {
    display: flex;
    gap: 1rem;
    align-items: center;
}

/* ============================================
   BUTTONS
   ============================================ */
.btn {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: var(--border-radius);
    font-family: var(--font-body);
    font-size: 1rem;
    cursor: pointer;
    transition: all var(--transition-speed);
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.btn-primary {
    background: var(--accent);
    color: white;
}

.btn-primary:hover:not(:disabled) {
    opacity: 0.9;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}

.btn-secondary {
    background: var(--primary-gray);
    color: white;
}

.btn-secondary:hover:not(:disabled) {
    opacity: 0.9;
}

.btn-outline {
    background: transparent;
    border: 2px solid var(--accent);
    color: var(--accent);
}

.btn-outline:hover:not(:disabled) {
    background: var(--accent);
    color: white;
}

.btn-icon {
    padding: 0.5rem;
    width: 40px;
    height: 40px;
    justify-content: center;
}

.btn-sm {
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
}

.btn-lg {
    padding: 1rem 2rem;
    font-size: 1.125rem;
}

/* ============================================
   UTILITY CLASSES
   ============================================ */
.hidden {
    display: none !important;
}

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

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

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

.text-muted {
    color: var(--text-muted);
}

/* Margins */
.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }

.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }

.ml-1 { margin-left: 0.5rem; }
.ml-2 { margin-left: 1rem; }
.mr-1 { margin-right: 0.5rem; }
.mr-2 { margin-right: 1rem; }

/* Padding */
.p-1 { padding: 0.5rem; }
.p-2 { padding: 1rem; }
.p-3 { padding: 1.5rem; }
.p-4 { padding: 2rem; }

/* Flexbox */
.flex {
    display: flex;
}

.flex-between {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.flex-center {
    display: flex;
    justify-content: center;
    align-items: center;
}

.flex-column {
    display: flex;
    flex-direction: column;
}

.flex-wrap {
    flex-wrap: wrap;
}

.gap-1 { gap: 0.5rem; }
.gap-2 { gap: 1rem; }
.gap-3 { gap: 1.5rem; }
.gap-4 { gap: 2rem; }

/* ============================================
   ANIMATIONS
   ============================================ */
@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes slideIn {
    from { transform: translateY(-20px); opacity: 0; }
    to { transform: translateY(0); opacity: 1; }
}

@keyframes slideOut {
    from { transform: translateY(0); opacity: 1; }
    to { transform: translateY(-20px); opacity: 0; }
}

@keyframes pulse {
    0%, 100% { transform: scale(1); opacity: 1; }
    50% { transform: scale(1.05); opacity: 0.8; }
}

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

.fade-in {
    animation: fadeIn 0.3s ease;
}

.slide-in {
    animation: slideIn 0.3s ease;
}

/* ============================================
   LOADING STATES
   ============================================ */
.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid rgba(0,0,0,0.1);
    border-radius: 50%;
    border-top-color: var(--accent);
    animation: spin 1s linear infinite;
}

.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(255,255,255,0.9);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: var(--z-modal);
}

/* ============================================
   RESPONSIVE DESIGN
   ============================================ */
@media (max-width: 1024px) {
    .main-content {
        padding: 1.5rem;
    }
}

@media (max-width: 768px) {
    .sidebar {
        transform: translateX(-100%);
        transition: transform var(--transition-speed);
    }

    .sidebar.mobile-open {
        transform: translateX(0);
    }

    .main-content {
        margin-left: 0;
        padding: 1rem;
    }

    .top-bar {
        flex-direction: column;
        align-items: flex-start;
        gap: 1rem;
    }

    .top-bar-actions {
        width: 100%;
        flex-wrap: wrap;
    }

    h1 { font-size: 2rem; }
    h2 { font-size: 1.75rem; }
    h3 { font-size: 1.5rem; }
}

@media (max-width: 480px) {
    .main-content {
        padding: 0.75rem;
    }

    .btn {
        padding: 0.5rem 1rem;
        font-size: 0.875rem;
    }
}

/* ============================================
   PRINT STYLES
   ============================================ */
@media print {
    .sidebar,
    .top-bar-actions,
    .btn {
        display: none !important;
    }

    .main-content {
        margin-left: 0;
    }

    .card {
        box-shadow: none;
        border: 1px solid var(--border-color);
    }
}