:root {
    --bg-dark: #0f172a;
    --card-bg-front: #1e293b;
    --card-bg-back: #0f172a;
    --accent-glow: #38bdf8;
    --text-main: #f8fafc;
    --text-muted: #94a3b8;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg-dark);
    color: var(--text-main);
    min-height: 100vh;
    padding: 3rem 1.5rem;
    display: flex;
    flex-direction: column;
    align-items: center;
}

header {
    text-align: center;
    margin-bottom: 4rem;
    max-width: 800px;
}

header h1 {
    font-size: 2.5rem;
    font-weight: 800;
    letter-spacing: -0.05em;
    margin-bottom: 1rem;
    background: linear-gradient(to right, #38bdf8, #818cf8);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

header p {
    color: var(--text-muted);
    font-size: 1.1rem;
    line-height: 1.6;
}

/* 4x4 Grid System */
.grid-container {
    display: grid;
    grid-template-columns: repeat(1, minmax(0, 1fr));
    gap: 2rem;
    max-width: 1200px;
    width: 100%;
}

/* Responsive Breakpoints */
@media (min-width: 640px) { 
    .grid-container { grid-template-columns: repeat(2, minmax(0, 1fr)); } 
}
@media (min-width: 1024px) { 
    .grid-container { grid-template-columns: repeat(4, minmax(0, 1fr)); } 
}

/* 3D Flip Card Architecture */
.card-perspective {
    perspective: 1000px;
    height: 290px; /* Slightly padded to safely accommodate content dimensions */
    width: 100%;
}

.card-inner {
    position: relative;
    width: 100%;
    height: 100%;
    text-align: left;
    transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
    transform-style: preserve-3d;
    cursor: pointer;
}

/* Hover Triggering the 180-degree flip */
.card-perspective:hover .card-inner {
    transform: rotateY(180deg);
}

.card-front, .card-back {
    position: absolute;
    width: 100%;
    height: 100%;
    -webkit-backface-visibility: hidden;
    backface-visibility: hidden;
    border-radius: 16px;
    padding: 1.75rem;
    display: flex;
    flex-direction: column;
    border: 1px solid rgba(255, 255, 255, 0.05);
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.2);
}

/* Card Front Layout */
.card-front {
    background-color: var(--card-bg-front);
    justify-content: space-between;
}

.card-content-wrapper {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.card-front .icon {
    font-size: 2rem;
    background: rgba(56, 189, 248, 0.1);
    color: var(--accent-glow);
    width: 50px;
    height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 12px;
    margin-bottom: 0.5rem;
}

.card-front h2 {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-main);
}

.card-front p {
    color: var(--text-muted);
    font-size: 0.9rem;
    line-height: 1.5;
    margin-top: 0.25rem;
}

.hint-text {
    font-size: 0.8rem;
    color: var(--accent-glow);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    display: flex;
    align-items: center;
    gap: 4px;
    margin-top: auto;
    padding-top: 1rem;
}

/* Card Back Layout (Rotated 180deg natively) */
.card-back {
    background-color: var(--card-bg-back);
    transform: rotateY(180deg);
    justify-content: center;
    border: 1px solid rgba(56, 189, 248, 0.2);
}

.card-back h3 {
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--accent-glow);
    margin-bottom: 0.75rem;
}

.endpoint-box {
    background: rgba(0, 0, 0, 0.3);
    border: 1px solid rgba(255, 255, 255, 0.1);
    padding: 0.75rem;
    border-radius: 8px;
    font-family: monospace;
    font-size: 0.85rem;
    word-break: break-all;
    color: #e2e8f0;
    margin-bottom: 1rem;
}

.copy-hint {
    font-size: 0.75rem;
    color: var(--text-muted);
    text-align: center;
}

/* Empty/Future Card Placeholder State */
.placeholder .card-front {
    background: rgba(30, 41, 59, 0.3);
    border: 1px dashed rgba(255, 255, 255, 0.1);
    justify-content: center;
    align-items: center;
    cursor: default;
}

.placeholder .card-front p {
    text-align: center;
    color: rgba(148, 163, 184, 0.4);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
}

/* Booking Section Styling */
.booking-section {
    max-width: 1200px;
    width: 100%;
    margin-top: 4rem;
    background: rgba(30, 41, 59, 0.4);
    border: 1px solid rgba(255, 255, 255, 0.05);
    border-radius: 24px;
    padding: 2.5rem;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
}

.booking-section h2 {
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    background: linear-gradient(to right, #38bdf8, #818cf8);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.booking-section p {
    color: var(--text-muted);
    font-size: 1rem;
    margin-bottom: 2rem;
}

#inline-container {
    width: 100%;
    background: #ffffff;
    border-radius: 16px;
    overflow: hidden;
    box-shadow: inset 0 2px 4px rgba(0,0,0,0.06);
}

@media (max-width: 640px) {
    .booking-section {
        padding: 1.5rem;
        margin-top: 2.5rem;
    }
}