:root {
    --bg-base: #050505;
    --bg-surface: #111111;
    --bg-surface-hover: #1a1a1a;
    --border-color: #222222;
    --text-primary: #ffffff;
    --text-secondary: #888888;
    --accent: #ffffff;
    --accent-hover: #dddddd;
    --danger: #ff453a;
    --success: #32d74b;
    --radius: 12px;
}

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

body {
    font-family: 'Inter', -apple-system, sans-serif;
    background-color: var(--bg-base);
    color: var(--text-primary);
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
}

.container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 2rem;
}

/* Typography */
h1, h2, h3 {
    font-weight: 500;
    letter-spacing: -0.02em;
}

h1 { font-size: 2rem; }
h2 { font-size: 1.5rem; margin-bottom: 1rem; }
h3 { font-size: 1.125rem; margin-bottom: 0.5rem; }

.text-muted { color: var(--text-secondary); }
.error-text { color: var(--danger); font-size: 0.875rem; margin-top: 0.5rem; }
.mb-4 { margin-bottom: 1rem; }
.section-title { margin-top: 2rem; margin-bottom: 1rem; border-bottom: 1px solid var(--border-color); padding-bottom: 0.5rem; }

.huge-balance {
    font-size: 4rem;
    font-weight: 300;
    letter-spacing: -0.04em;
    margin: 1rem 0;
}
.huge-balance.positive { color: var(--success); }
.huge-balance.negative { color: var(--danger); }

/* Forms & Inputs */
input {
    width: 100%;
    padding: 0.75rem 1rem;
    background: var(--bg-base);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    color: var(--text-primary);
    font-family: inherit;
    font-size: 1rem;
    outline: none;
    transition: all 0.2s ease;
}

input:focus {
    border-color: var(--text-secondary);
}

.form-group { margin-bottom: 1rem; }
.form-group label { display: block; margin-bottom: 0.5rem; color: var(--text-secondary); font-size: 0.875rem; }
.form-row { display: flex; gap: 1rem; align-items: center; }

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: var(--radius);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
}

.btn:disabled { opacity: 0.5; cursor: not-allowed; }
.btn.primary { background: var(--accent); color: var(--bg-base); }
.btn.primary:hover:not(:disabled) { background: var(--accent-hover); }
.btn.secondary { background: var(--bg-surface); color: var(--text-primary); border: 1px solid var(--border-color); }
.btn.secondary:hover:not(:disabled) { background: var(--bg-surface-hover); }
.btn.danger { background: rgba(255, 69, 58, 0.1); color: var(--danger); }
.btn.danger:hover:not(:disabled) { background: rgba(255, 69, 58, 0.2); }
.btn.sm { padding: 0.4rem 0.8rem; font-size: 0.75rem; }
.full-width { width: 100%; }

/* Header & Nav */
header {
    border-bottom: 1px solid var(--border-color);
    background: var(--bg-surface);
    padding: 1rem 2rem;
}
.header-content {
    max-width: 1000px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.header-content h1 { font-size: 1.25rem; font-weight: 600; }
nav { display: flex; gap: 1.5rem; }
.nav-btn {
    background: none; border: none; color: var(--text-secondary); cursor: pointer; font-size: 0.875rem; transition: color 0.2s;
}
.nav-btn:hover, .nav-btn.active { color: var(--text-primary); }

/* Layouts & Cards */
.card {
    background: var(--bg-surface);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    padding: 1.5rem;
}
.action-bar { display: flex; gap: 1rem; margin-bottom: 2rem; }
.action-bar input { flex: 1; }

/* Grid */
.players-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 1.5rem;
}
.player-card {
    background: var(--bg-surface);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    padding: 1.5rem;
    transition: transform 0.2s ease, border-color 0.2s ease;
    cursor: pointer;
    display: flex;
    flex-direction: column;
}
.player-card:hover {
    transform: translateY(-2px);
    border-color: var(--text-secondary);
}
.player-card-header { display: flex; justify-content: space-between; align-items: flex-start; margin-bottom: 1rem; }
.player-card-title { font-weight: 500; font-size: 1.125rem; }
.player-balance { font-size: 1.5rem; font-weight: 300; margin-bottom: 1.5rem; }
.player-balance.positive { color: var(--success); }
.player-balance.negative { color: var(--danger); }
.player-actions { display: flex; gap: 0.5rem; margin-top: auto; }

/* Session List Items */
.session-item {
    background: var(--bg-surface);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    padding: 1.5rem;
    margin-bottom: 1rem;
}
.session-header {
    display: flex;
    justify-content: space-between;
    margin-bottom: 1rem;
    color: var(--text-secondary);
    font-size: 0.875rem;
}
.session-players {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 1rem;
}
.session-player-card {
    background: var(--bg-base);
    padding: 1rem;
    border-radius: 8px;
    border: 1px solid var(--border-color);
}
.session-player-card .name { font-weight: 500; margin-bottom: 0.5rem; }
.session-player-card .amounts { font-size: 0.875rem; color: var(--text-secondary); }
.session-player-card .profit { font-weight: 500; margin-top: 0.5rem; }
.profit.positive { color: var(--success); }
.profit.negative { color: var(--danger); }

/* Modals */
.modal {
    display: none; position: fixed; top: 0; left: 0; width: 100%; height: 100%;
    background: rgba(0,0,0,0.8); backdrop-filter: blur(8px);
    align-items: center; justify-content: center; z-index: 100;
}
.modal.active { display: flex; }
.modal-content {
    background: var(--bg-base);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 2rem;
    width: 90%;
    max-width: 400px;
}
.modal-content.large { max-width: 600px; max-height: 90vh; overflow-y: auto; }
.modal-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 1.5rem; }
.close-btn { background: none; border: none; color: var(--text-secondary); font-size: 1.5rem; cursor: pointer; }
.modal-actions { display: flex; justify-content: flex-end; gap: 1rem; margin-top: 1.5rem; }

/* Session Player Rows in Modal */
.session-players-list { margin: 1.5rem 0; border: 1px solid var(--border-color); border-radius: var(--radius); overflow: hidden; }
.session-row { display: flex; gap: 1rem; padding: 1rem; border-bottom: 1px solid var(--border-color); align-items: center; background: var(--bg-surface); }
.session-row:last-child { border-bottom: none; }
.session-row label { flex: 1; display: flex; align-items: center; gap: 0.75rem; cursor: pointer; }
.session-row input[type="number"] { width: 120px; }
.session-row.disabled { opacity: 0.4; }
.session-row.disabled input[type="number"] { pointer-events: none; }
.session-summary { display: flex; justify-content: space-between; padding: 1rem; background: var(--bg-surface); border-radius: var(--radius); margin-bottom: 1.5rem; font-weight: 500; }

/* Login */
.login-container {
    max-width: 400px;
    margin: 10vh auto;
    text-align: center;
}
.login-container h1 { margin-bottom: 0.5rem; }
.login-container p { color: var(--text-secondary); margin-bottom: 2rem; }
.login-container form { display: flex; flex-direction: column; gap: 1rem; }

/* Utilities */
.view { display: none; }
.view.active { display: block; }
.tab-content { display: none; }
.tab-content.active { display: block; }