/* ========== RESET & BASE ========== */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --bg-dark: #0a0a0f;
    --bg-card: #14141f;
    --accent: #f59e0b;
    --accent-glow: #f59e0b88;
    --danger: #ef4444;
    --success: #22c55e;
    --text: #e2e8f0;
    --text-dim: #64748b;
    --bucket-wood: #5c3a1e;
    --bucket-wood-dark: #3a2010;
    --bucket-wood-light: #7a4c28;
    --bucket-rim: #8B6914;
    --letter-bg: #1e293b;
    --letter-border: #334155;
    --letter-selected: #f59e0b;
    --letter-selected-bg: #78350f;
    --letter-invalid: #ef4444;
}

html, body {
    width: 100%;
    height: 100%;
    overflow: hidden;
    background: var(--bg-dark);
    color: var(--text);
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    user-select: none;
    -webkit-user-select: none;
    cursor: default;
}

/* ========== SCREENS ========== */
.screen {
    position: fixed;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.4s ease;
    z-index: 10;
}

.screen.active {
    opacity: 1;
    pointer-events: all;
    z-index: 20;
}

/* ========== SPLASH ========== */
#splash-screen {
    background: var(--bg-dark);
    z-index: 100;
}

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

#splash-logo {
    width: 180px;
    height: 180px;
    object-fit: contain;
    margin-bottom: 20px;
    animation: pulse-glow 2s ease-in-out infinite;
}

.splash-title {
    font-family: 'Russo One', sans-serif;
    font-size: 3.5rem;
    color: var(--accent);
    letter-spacing: 0.15em;
    text-shadow: 0 0 40px var(--accent-glow), 0 0 80px var(--accent-glow);
    margin-bottom: 30px;
}

.splash-loader {
    width: 200px;
    height: 4px;
    background: var(--bg-card);
    border-radius: 2px;
    margin: 0 auto;
    overflow: hidden;
}

.loader-bar {
    width: 0%;
    height: 100%;
    background: var(--accent);
    border-radius: 2px;
    animation: load-progress 2.8s ease-in-out forwards;
}

@keyframes load-progress {
    0% { width: 0%; }
    60% { width: 70%; }
    100% { width: 100%; }
}

@keyframes pulse-glow {
    0%, 100% { filter: drop-shadow(0 0 10px var(--accent-glow)); }
    50% { filter: drop-shadow(0 0 25px var(--accent-glow)); }
}

/* ========== MENU ========== */
#menu-screen {
    background: var(--bg-dark);
    background-image: radial-gradient(ellipse at 50% 30%, #1a1a2e 0%, var(--bg-dark) 70%);
}

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

.menu-title {
    font-family: 'Russo One', sans-serif;
    font-size: 4rem;
    color: var(--accent);
    letter-spacing: 0.15em;
    text-shadow: 0 0 40px var(--accent-glow);
    margin-bottom: 10px;
}

.menu-subtitle {
    color: var(--text-dim);
    font-size: 1rem;
    margin-bottom: 40px;
    font-style: italic;
}

.btn-primary {
    display: block;
    width: 220px;
    margin: 0 auto 15px;
    padding: 16px 40px;
    font-family: 'Russo One', sans-serif;
    font-size: 1.3rem;
    letter-spacing: 0.1em;
    color: var(--bg-dark);
    background: var(--accent);
    border: none;
    border-radius: 12px;
    cursor: pointer;
    transition: transform 0.15s, box-shadow 0.15s;
    box-shadow: 0 4px 20px var(--accent-glow);
}

.btn-primary:hover {
    transform: scale(1.05);
    box-shadow: 0 6px 30px var(--accent-glow);
}

.btn-secondary {
    display: block;
    width: 220px;
    margin: 0 auto;
    padding: 12px 40px;
    font-family: 'Inter', sans-serif;
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-dim);
    background: transparent;
    border: 2px solid var(--text-dim);
    border-radius: 12px;
    cursor: pointer;
    transition: transform 0.15s, border-color 0.15s, color 0.15s;
}

.btn-secondary:hover {
    transform: scale(1.05);
    border-color: var(--text);
    color: var(--text);
}

.high-score-display {
    margin-top: 30px;
    display: flex;
    flex-direction: column;
    gap: 4px;
    color: var(--text-dim);
    font-size: 0.9rem;
}

.high-score-display span:last-child {
    font-size: 1.5rem;
    font-weight: 900;
    color: var(--accent);
}

/* ========== GAME ========== */
#game-screen {
    background: var(--bg-dark);
}

#game-container {
    position: relative;
    width: 100vw;
    max-width: 480px;
    height: 100vh;
    max-height: 850px;
    margin: 0 auto;
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

/* Score Bar */
#score-bar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px 20px;
    background: var(--bg-card);
    border-bottom: 1px solid #1e293b;
    flex-shrink: 0;
    z-index: 5;
}

.score-left, .score-right {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 2px;
}

.score-label {
    font-size: 0.65rem;
    font-weight: 700;
    letter-spacing: 0.15em;
    color: var(--text-dim);
}

#current-score, #current-level {
    font-family: 'Russo One', sans-serif;
    font-size: 1.4rem;
    color: var(--accent);
}

.score-center {
    flex: 1;
    text-align: center;
}

#current-word-display {
    font-family: 'Russo One', sans-serif;
    font-size: 1.6rem;
    letter-spacing: 0.12em;
    color: var(--text);
    text-transform: uppercase;
    min-height: 1.6rem;
    transition: color 0.2s;
}

#current-word-display.valid-prefix {
    color: var(--success);
}

#current-word-display.invalid-prefix {
    color: var(--danger);
}

/* Fall Zone */
#fall-zone {
    flex: 1;
    position: relative;
    min-height: 100px;
    overflow: hidden;
}

.falling-letter {
    position: absolute;
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: 'Russo One', sans-serif;
    font-size: 1.3rem;
    color: var(--text);
    background: var(--letter-bg);
    border: 2px solid var(--letter-border);
    border-radius: 8px;
    transition: top linear;
    animation: wobble 1.5s ease-in-out infinite;
    z-index: 2;
    pointer-events: none;
}

@keyframes wobble {
    0%, 100% { transform: translateX(0) rotate(0deg); }
    25% { transform: translateX(-3px) rotate(-2deg); }
    75% { transform: translateX(3px) rotate(2deg); }
}

/* ========== 3D BUCKET ========== */
#bucket-wrapper {
    flex-shrink: 0;
    padding: 0 15px 20px;
    perspective: 600px;
    perspective-origin: 50% 20%;
}

#bucket {
    position: relative;
    transform: rotateX(6deg);
    transform-style: preserve-3d;
    background: linear-gradient(180deg, var(--bucket-wood-dark) 0%, var(--bucket-wood) 40%, var(--bucket-wood-dark) 100%);
    border: 3px solid var(--bucket-rim);
    border-top: 4px solid var(--bucket-rim);
    border-radius: 4px 4px 14px 14px;
    clip-path: polygon(4% 0%, 96% 0%, 100% 100%, 0% 100%);
    padding: 8px;
    min-height: 200px;
    transition: border-color 0.3s;
}

#bucket.danger {
    border-color: var(--danger);
    animation: bucket-pulse 0.8s ease-in-out infinite;
}

@keyframes bucket-pulse {
    0%, 100% { box-shadow: 0 0 10px transparent; }
    50% { box-shadow: 0 0 20px rgba(239, 68, 68, 0.4); }
}

.bucket-wall {
    position: absolute;
    top: 0;
    width: 18px;
    height: 100%;
    background: linear-gradient(180deg, var(--bucket-wood-light) 0%, var(--bucket-wood-dark) 100%);
    z-index: 1;
}

#bucket-wall-left {
    left: -2px;
    transform: rotateY(20deg);
    transform-origin: right center;
    border-radius: 4px 0 0 12px;
    border-left: 2px solid var(--bucket-rim);
}

#bucket-wall-right {
    right: -2px;
    transform: rotateY(-20deg);
    transform-origin: left center;
    border-radius: 0 4px 12px 0;
    border-right: 2px solid var(--bucket-rim);
}

#bucket-floor {
    position: absolute;
    bottom: 0;
    left: 5%;
    right: 5%;
    height: 6px;
    background: var(--bucket-wood-dark);
    border-radius: 0 0 10px 10px;
    transform: rotateX(60deg);
    transform-origin: bottom center;
}

/* Letter Grid inside Bucket */
#letter-grid {
    display: grid;
    grid-template-columns: repeat(6, 1fr);
    gap: 4px;
    position: relative;
    z-index: 2;
    direction: ltr;
}

.grid-letter {
    aspect-ratio: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: 'Russo One', sans-serif;
    font-size: 1.3rem;
    color: var(--text);
    background: var(--letter-bg);
    border: 2px solid var(--letter-border);
    border-radius: 8px;
    cursor: pointer;
    transition: transform 0.15s, background 0.15s, border-color 0.15s, box-shadow 0.15s;
    position: relative;
}

.grid-letter:hover {
    border-color: var(--text-dim);
}

.grid-letter .letter-points {
    position: absolute;
    bottom: 2px;
    right: 4px;
    font-size: 0.55rem;
    color: var(--text-dim);
    font-family: 'Inter', sans-serif;
    font-weight: 700;
}

.grid-letter.selected {
    background: var(--letter-selected-bg);
    border-color: var(--letter-selected);
    box-shadow: 0 0 12px var(--accent-glow);
    transform: scale(1.08);
    z-index: 3;
}

.grid-letter.landing {
    animation: land-bounce 0.3s ease-out;
}

@keyframes land-bounce {
    0% { transform: scale(1.2); }
    50% { transform: scale(0.95); }
    100% { transform: scale(1); }
}

.grid-letter.explode {
    animation: explode 0.4s ease-out forwards;
}

@keyframes explode {
    0% { transform: scale(1); opacity: 1; }
    50% { transform: scale(1.4); opacity: 0.7; }
    100% { transform: scale(0); opacity: 0; }
}

.grid-letter.shake {
    animation: shake 0.4s ease-out;
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    20% { transform: translateX(-6px); }
    40% { transform: translateX(6px); }
    60% { transform: translateX(-4px); }
    80% { transform: translateX(4px); }
}

.grid-letter.invalid {
    border-color: var(--danger);
    background: rgba(239, 68, 68, 0.15);
}

/* Selection Line SVG */
#selection-svg {
    position: absolute;
    inset: 0;
    z-index: 4;
    pointer-events: none;
}

#selection-svg line {
    stroke: var(--accent);
    stroke-width: 3;
    stroke-linecap: round;
    opacity: 0.7;
}

/* Float Score */
#float-scores {
    position: absolute;
    inset: 0;
    pointer-events: none;
    z-index: 50;
}

.float-score {
    position: absolute;
    font-family: 'Russo One', sans-serif;
    font-size: 1.4rem;
    color: var(--success);
    text-shadow: 0 0 10px rgba(34, 197, 94, 0.5);
    animation: float-up 1s ease-out forwards;
    pointer-events: none;
}

.float-word {
    position: absolute;
    font-family: 'Russo One', sans-serif;
    font-size: 1rem;
    color: var(--accent);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    animation: float-up 1.2s ease-out forwards;
    pointer-events: none;
}

@keyframes float-up {
    0% { transform: translateY(0); opacity: 1; }
    100% { transform: translateY(-80px); opacity: 0; }
}

/* ========== GAME OVER ========== */
#gameover-screen {
    background: rgba(10, 10, 15, 0.92);
    backdrop-filter: blur(8px);
}

.gameover-content {
    text-align: center;
    padding: 30px;
}

.gameover-title {
    font-family: 'Russo One', sans-serif;
    font-size: 3rem;
    color: var(--danger);
    letter-spacing: 0.1em;
    text-shadow: 0 0 30px rgba(239, 68, 68, 0.4);
    margin-bottom: 30px;
}

.gameover-stats {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
    margin-bottom: 35px;
    max-width: 300px;
    margin-left: auto;
    margin-right: auto;
}

.stat {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.stat-label {
    font-size: 0.75rem;
    font-weight: 700;
    letter-spacing: 0.12em;
    color: var(--text-dim);
    text-transform: uppercase;
}

.stat-value {
    font-family: 'Russo One', sans-serif;
    font-size: 1.6rem;
    color: var(--accent);
}

/* ========== AUTH SCREEN ========== */
#auth-screen {
    background: var(--bg-dark);
    background-image: radial-gradient(ellipse at 50% 30%, #1a1a2e 0%, var(--bg-dark) 70%);
}

.auth-content {
    text-align: center;
    width: 100%;
    max-width: 360px;
    padding: 20px;
}

.auth-title {
    font-family: 'Russo One', sans-serif;
    font-size: 2.5rem;
    color: var(--accent);
    letter-spacing: 0.15em;
    text-shadow: 0 0 30px var(--accent-glow);
    margin-bottom: 30px;
}

.auth-form {
    background: var(--bg-card);
    border: 1px solid #1e293b;
    border-radius: 16px;
    padding: 25px;
    margin-bottom: 15px;
}

.auth-form-title {
    font-family: 'Russo One', sans-serif;
    font-size: 1.2rem;
    color: var(--text);
    margin-bottom: 20px;
}

.auth-form input {
    display: block;
    width: 100%;
    padding: 12px 16px;
    margin-bottom: 12px;
    font-family: 'Inter', sans-serif;
    font-size: 0.95rem;
    color: var(--text);
    background: var(--bg-dark);
    border: 2px solid var(--letter-border);
    border-radius: 10px;
    outline: none;
    transition: border-color 0.2s;
}

.auth-form input:focus {
    border-color: var(--accent);
}

.auth-form input::placeholder {
    color: var(--text-dim);
}

.auth-error {
    color: var(--danger);
    font-size: 0.85rem;
    min-height: 1.2em;
    margin-bottom: 10px;
}

.auth-switch {
    margin-top: 15px;
    font-size: 0.85rem;
    color: var(--text-dim);
}

.auth-switch a {
    color: var(--accent);
    text-decoration: none;
    font-weight: 600;
}

.auth-switch a:hover {
    text-decoration: underline;
}

#skip-auth-btn {
    margin-top: 10px;
}

/* ========== USER BADGE ========== */
.user-badge {
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
    font-size: 0.9rem;
}

.user-badge span {
    color: var(--accent);
    font-weight: 700;
}

.user-badge a {
    color: var(--text-dim);
    text-decoration: none;
    font-size: 0.8rem;
}

.user-badge a:hover {
    color: var(--danger);
}

/* ========== PROFILE SCREEN ========== */
#profile-screen {
    background: var(--bg-dark);
    background-image: radial-gradient(ellipse at 50% 30%, #1a1a2e 0%, var(--bg-dark) 70%);
    overflow-y: auto;
}

.profile-content {
    text-align: center;
    width: 100%;
    max-width: 400px;
    padding: 30px 20px;
}

.profile-title {
    font-family: 'Russo One', sans-serif;
    font-size: 1.8rem;
    color: var(--accent);
    margin-bottom: 5px;
}

.profile-username {
    color: var(--text-dim);
    font-size: 1rem;
    margin-bottom: 25px;
}

.profile-stats {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    gap: 15px;
    margin-bottom: 30px;
}

.profile-section-title {
    font-family: 'Russo One', sans-serif;
    font-size: 1rem;
    color: var(--text);
    margin-bottom: 15px;
    text-align: left;
}

.profile-history {
    margin-bottom: 25px;
}

.history-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px 14px;
    background: var(--bg-card);
    border: 1px solid #1e293b;
    border-radius: 10px;
    margin-bottom: 8px;
    font-size: 0.85rem;
}

.history-item .history-score {
    font-family: 'Russo One', sans-serif;
    font-size: 1.1rem;
    color: var(--accent);
}

.history-item .history-date {
    color: var(--text-dim);
    font-size: 0.75rem;
}

.history-item .history-words {
    color: var(--text-dim);
}

#profile-back-btn {
    margin-top: 10px;
}

/* ========== SPLASH PARTICLES (letter landing) ========== */
#splash-particles {
    position: absolute;
    inset: 0;
    pointer-events: none;
    z-index: 40;
    overflow: visible;
}

.splash-particle {
    position: absolute;
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--accent);
    opacity: 0.9;
    animation: splash-fly 0.6s ease-out forwards;
    pointer-events: none;
}

@keyframes splash-fly {
    0% {
        transform: translate(0, 0) scale(1);
        opacity: 0.9;
    }
    100% {
        transform: translate(var(--dx), var(--dy)) scale(0);
        opacity: 0;
    }
}

/* ========== RESPONSIVE ========== */
@media (max-width: 400px) {
    .splash-title, .menu-title {
        font-size: 2.8rem;
    }
    .grid-letter {
        font-size: 1.1rem;
    }
    #current-word-display {
        font-size: 1.3rem;
    }
}

@media (min-width: 768px) {
    #game-container {
        border-left: 1px solid #1e293b;
        border-right: 1px solid #1e293b;
    }
}