/* ==========================================================================
   EXPERT PALETTE: Slate Arctic (Elegant & Professional)
   ========================================================================== */
:root {
    --primary-color: #264653;   /* Slate Charcoal */
    --accent-color: #2A9D8F;    /* Arctic Teal */
    --border-subtle: #bfe1e5;   /* Subtle divider color */
    --bg-secondary: #fbfcfc;    /* Off-white depth */
    --dot-color: #E76F51;       /* Warm Coral Accent */
    --text-main: #2d3436;
    --text-muted: #636e72;
    --white: #ffffff;
    --nav-height: 75px;
}

/* ==========================================================================
   GLOBAL FIXES & TYPOGRAPHY
   ========================================================================== */
html {
    scroll-behavior: smooth;
    scroll-padding-top: var(--nav-height); 
}

body {
    font-family: 'Inter', -apple-system, sans-serif;
    line-height: 1.7;
    color: var(--text-main);
    background-color: var(--white);
    margin: 0;
    -webkit-font-smoothing: antialiased;
}

h1, h2, h3 {
    letter-spacing: -0.02em; 
    font-weight: 700;
}

/* Smooth Transition for all interactive elements */
.card, .resource-card, .roadmap-tile, .btn, .nav-links a {
    transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
}

/* ==========================================================================
   RESPONSIVE NAVIGATION (Glassmorphism)
   ========================================================================== */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    min-height: var(--nav-height);
    background: rgba(255, 255, 255, 0.8) !important;
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-subtle);
    display: flex;
    align-items: center;
    z-index: 1000;
    padding: 10px 0;
}

.nav-container {
    width: 90%;
    max-width: 1100px;
    margin: auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
}

.logo {
    text-decoration: none;
    color: var(--primary-color);
    font-weight: 700;
    font-size: 1rem;
    letter-spacing: 0.05rem;
    text-transform: uppercase;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 30px;
    margin: 0;
    padding: 0;
    flex-wrap: wrap;
    justify-content: center;
}

.nav-links a {
    text-decoration: none;
    color: var(--primary-color);
    font-weight: 600;
    font-size: 0.8rem;
    text-transform: uppercase;
}

.nav-links a:hover { color: var(--accent-color); }

/* ==========================================================================
   HERO SECTION
   ========================================================================== */
.hero {
    background-color: var(--bg-secondary);
    background-image: radial-gradient(var(--border-subtle) 1px, transparent 1px);
    background-size: 30px 30px; 
    padding: 140px 20px 80px;
}

.hero-container {
    max-width: 1100px;
    margin: auto;
    display: grid;
    grid-template-columns: 280px 1fr;
    gap: 60px;
    align-items: center;
}

.hero-image img {
    width: 260px;
    height: 260px;
    border-radius: 50%;
    object-fit: cover;
    border: 4px solid var(--primary-color);
    box-shadow: 0 10px 25px rgba(0,0,0,0.05);
}

.hero h1 { 
    font-size: 2.4rem; 
    color: var(--primary-color); 
    margin: 0 0 10px;
}

.subtitle { 
    font-size: 1.2rem; 
    color: var(--text-muted); 
    margin-bottom: 25px; 
}

.hero-quote { 
    font-size: 1.1rem;      
    font-style: italic;
    color: var(--text-muted);
    border-left: 2px solid var(--accent-color);
    padding-left: 20px;
}

/* ==========================================================================
   PROFESSIONAL JOURNEY (Timeline)
   ========================================================================== */
.timeline { 
    position: relative;
    margin-left: 10px; 
    padding: 20px 0;
}

.timeline::before {
    content: '';
    position: absolute;
    left: -1px; 
    top: 30px;
    bottom: 30px;
    width: 1px;
    background-color: var(--border-subtle);
    z-index: 0;
}

.timeline-item { 
    position: relative; 
    padding-left: 30px; 
    margin-bottom: 40px; 
    z-index: 1;
}

.timeline-dot { 
    position: absolute; 
    left: -5px; 
    top: 8px; 
    width: 9px; 
    height: 9px; 
    background: var(--dot-color); 
    border-radius: 50%;
    z-index: 2;
}

.timeline-date { 
    font-size: 0.75rem; 
    font-weight: 700; 
    color: var(--accent-color); 
}

/* ==========================================================================
   SECTION COMMONS & GRIDS
   ========================================================================== */
.section { 
    padding: 80px 5%; 
    max-width: 1100px; 
    margin: auto; 
}

.section-title { 
    font-size: 1.8rem; 
    color: var(--primary-color); 
    margin-bottom: 40px; 
}

.resource-grid, .roadmap-grid { 
    display: grid; 
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); 
    gap: 30px; 
    width: 100%;
}

/* ==========================================================================
   CARDS & TILES (The "Lift" Layer)
   ========================================================================== */
.card, .resource-card, .roadmap-tile { 
    background: var(--white); 
    border: 2px solid var(--border-subtle); 
    padding: 30px; 
}

.roadmap-tile {
    background: var(--bg-secondary);
    border: none;
    border-top: 4px solid var(--accent-color);
    border-radius: 0 0 4px 4px;
}

.card:hover, .resource-card:hover, .roadmap-tile:hover {
    transform: translateY(-6px);
    border-color: var(--accent-color);
    background: var(--white);
    box-shadow: 0 15px 35px rgba(38, 70, 83, 0.1);
}

.math-tag {
    display: inline-block;
    background: var(--bg-secondary);
    color: var(--primary-color);
    padding: 4px 10px;
    font-size: 0.7rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 15px;
    border-left: 3px solid var(--accent-color);
}

.tile-id {
    font-size: 0.7rem;
    font-weight: 800;
    color: var(--accent-color);
    text-transform: uppercase;
    letter-spacing: 2px;
    margin-bottom: 10px;
}

/* ==========================================================================
   BUTTONS & DROPDOWN
   ========================================================================== */
.btn {
    border: 1px solid var(--primary-color);
    color: var(--primary-color) !important;
    padding: 10px 20px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    text-decoration: none;
    display: inline-block;
}

.btn:hover { background: var(--primary-color); color: var(--white) !important; }

.dropdown {
    position: relative;
    display: inline-block;
}

.dropdown-content {
    display: none;
    position: absolute;
    background-color: var(--white);
    min-width: 220px;
    box-shadow: 0px 8px 16px rgba(0,0,0,0.1);
    z-index: 1001;
    border: 1px solid var(--border-subtle);
    top: 100%;
    left: 0;
}

.dropdown-content a {
    color: var(--primary-color);
    padding: 12px 16px;
    text-decoration: none;
    display: block;
    font-size: 0.85rem;
    border-bottom: 1px solid #f9f9f9;
}

.dropdown-content a:hover {
    background-color: var(--bg-secondary);
    color: var(--accent-color);
}

@media (min-width: 1024px) {
    .dropdown:hover .dropdown-content { display: block; }
}

/* ==========================================================================
   MOBILE RESPONSIVENESS
   ========================================================================== */
@media (max-width: 768px) {
    .hero-container { grid-template-columns: 1fr; text-align: center; }
    .hero-image img { margin: auto; }
    
    .dropdown-content {
        position: static;
        box-shadow: none;
        border: none;
        background: var(--bg-secondary);
        width: 100%;
    }
}

#contact .btn {
    min-width: 250px;
    justify-content: center;
}