:root {
    --bg-color: #0d0d0d;
    --text-color: #e0e0e0;
    --accent-color: #cfd8dc;
    --btn-bg: rgba(255, 255, 255, 0.05);
    --btn-border: rgba(255, 255, 255, 0.2);
    --btn-bg-hover: rgba(255, 255, 255, 0.1);
    --input-bg: transparent;
    --input-border: #555;
    --error-color: #ff6b6b;
    --font-main: 'Outfit', sans-serif;
    --font-serif: 'Playfair Display', serif;

    /* Romantic Theme Vars */
    --rom-bg-gradient: linear-gradient(135deg, #4a0000 0%, #880e4f 50%, #ff6f00 100%);
}

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

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    font-family: var(--font-main);
    height: 100vh;
    overflow: hidden;
    display: flex;
    justify-content: center;
    align-items: center;
    transition: background 1.5s ease;
}

#app {
    width: 100%;
    max-width: 600px;
    height: 100vh;
    /* full viewport to control exact centering */
    position: relative;
    display: flex;
    justify-content: center;
    align-items: center;
    text-align: center;
}

/* Screens */
.screen {
    position: absolute;
    width: 100%;
    padding: 2rem;
    opacity: 0;
    pointer-events: none;
    transform: translateY(20px);
    transition: opacity 0.6s ease, transform 0.6s ease;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    height: 100%;
}

.screen.active {
    opacity: 1;
    pointer-events: all;
    transform: translateY(0);
}

.screen.exiting {
    opacity: 0;
    transform: translateY(-20px);
}

/* Typography */
h1 {
    font-weight: 300;
    font-size: 2.5rem;
    margin-bottom: 1rem;
    letter-spacing: -0.5px;
}

h2 {
    font-weight: 300;
    font-size: 1.8rem;
    margin-bottom: 2rem;
}

.subtitle {
    font-weight: 200;
    color: #aaa;
    margin-bottom: 3rem;
    font-size: 1.1rem;
}

/* Buttons */
.btn {
    background: var(--btn-bg);
    border: 1px solid var(--btn-border);
    color: var(--text-color);
    padding: 1rem 2.5rem;
    font-family: var(--font-main);
    font-size: 1rem;
    border-radius: 50px;
    cursor: pointer;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-top: 1rem;
}

.btn:hover {
    background: var(--btn-bg-hover);
    border-color: #fff;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
}

.btn.primary {
    background: #fff;
    color: #000;
    font-weight: 500;
    border: none;
}

.btn.primary:hover {
    background: #f0f0f0;
}

.btn.special {
    background: #fff;
    color: #000;
    border: 1px solid #fff;
    width: 100%;
    margin-top: 1.5rem;
    font-weight: 600;
}

.options-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
    width: 100%;
}

.options-row {
    display: flex;
    gap: 1rem;
    justify-content: center;
    width: 100%;
}

.btn.option {
    margin-top: 0;
    width: 100%;
    padding: 1rem;
    font-size: 0.95rem;
}

/* Inputs */
.input-group {
    margin-bottom: 1rem;
    width: 100%;
    max-width: 300px;
}

input[type="text"] {
    width: 100%;
    background: transparent;
    border: none;
    border-bottom: 1px solid var(--input-border);
    color: #fff;
    font-family: var(--font-main);
    font-size: 1.5rem;
    text-align: center;
    padding: 0.5rem;
    outline: none;
    transition: border-color 0.3s;
}

input[type="text"]:focus {
    border-bottom-color: #fff;
}

.error-msg {
    color: var(--error-color);
    font-size: 0.9rem;
    height: 1.2rem;
    opacity: 0;
    transition: opacity 0.3s;
    margin-bottom: 1rem;
}

.error-msg.visible {
    opacity: 1;
}

/* Slider */
.slider-container {
    width: 100%;
    max-width: 300px;
    margin-bottom: 2rem;
    text-align: center;
}

input[type=range] {
    -webkit-appearance: none;
    appearance: none;
    width: 100%;
    background: transparent;
}

input[type=range]::-webkit-slider-thumb {
    -webkit-appearance: none;
    height: 20px;
    width: 20px;
    border-radius: 50%;
    background: #fff;
    cursor: pointer;
    margin-top: -8px;
    box-shadow: 0 0 10px rgba(255, 255, 255, 0.5);
}

input[type=range]::-webkit-slider-runnable-track {
    width: 100%;
    height: 4px;
    cursor: pointer;
    background: #444;
    border-radius: 2px;
}

.slider-value {
    margin-top: 1.5rem;
    font-size: 1.5rem;
    font-weight: 300;
    font-variant-numeric: tabular-nums;
}

/* Modal */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.8);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 100;
    opacity: 1;
    transition: opacity 0.3s;
}

.modal.hidden {
    opacity: 0;
    pointer-events: none;
}

.modal-content {
    background: #1e1e1e;
    padding: 2rem;
    border-radius: 12px;
    text-align: center;
    border: 1px solid #333;
    max-width: 80%;
}

.modal-content p {
    font-size: 1.2rem;
    margin-bottom: 1.5rem;
}

/* Utility */
.hidden {
    display: none !important;
}

/* Final Screen */
.final-screen h1 {
    font-family: var(--font-serif);
    font-size: 3.5rem;
    color: #fff;
    text-shadow: 0 0 20px rgba(255, 215, 0, 0.5);
    margin-bottom: 1rem;
}

.final-content {
    position: relative;
    z-index: 10;
}

.romantic-sub {
    font-size: 1.5rem;
    opacity: 0.9;
}

body.romantic-mode {
    background: #4a0000;
    /* Fallback */
    background: var(--rom-bg-gradient);
    background-size: 200% 200%;
    animation: gradientBG 10s ease infinite;
}

@keyframes gradientBG {
    0% {
        background-position: 0% 50%;
    }

    50% {
        background-position: 100% 50%;
    }

    100% {
        background-position: 0% 50%;
    }
}

#canvas-effects {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 1;
}

/* Animations Utility */
.fade-in-up {
    animation: fadeInUp 1s ease forwards;
    opacity: 0;
    transform: translateY(20px);
}

.delay-1 {
    animation-delay: 0.2s;
}

.delay-2 {
    animation-delay: 0.4s;
}

@keyframes fadeInUp {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Music Toggle */
.music-toggle {
    position: fixed;
    top: 2rem;
    right: 2rem;
    z-index: 50;
    cursor: pointer;
    color: #fff;
    opacity: 0.5;
    transition: opacity 0.3s;
}

.music-toggle:hover {
    opacity: 1;
}